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Author Topic: Cycling A Freshwater Tank  (Read 53027 times)
« on: August 27, 2006, 07:03:58 PM »

Cycling A Tank

Here on the boards a lot of time, attention, and effort is given to helping folks cycle a tank. The cycle sticky in the newbie forum is loaded with excellent information, but has become large enough that it is hard to use as a guide, and very few people reading page #8 remember or know what was on page #3. It also omits some , as it wasn?t originally written as an article. These Omissions generate more questions and so on. With that in mind I thought I?d put together a clear concise article to be used for cycling information. I am organizing this in outline format, so people can jump to the section that applies to their specific situation and get information quickly. There will be a lot of links throughout this article. The links will give detailed information on specifics as well. Please use the links and information others have written to your benefit. I will give a lot of overview information, the links will contain specifics and in depth info for folks to read and consider. The cycle sticky is still a very valuable tool and will be linked for the purpose of use. Please take the time to read it when you have an opportunity, I know it?s long, but this is a big subject with a lot of options. This article is by no means short, and I highly recommend it be used like a manual. Find the heading that applies to your question and read that section. For instance if you don?t know which type of cycle you want to do go to the section on types of cycles. After deciding, go to the section on that particular cycle, after starting go to the additional info sections, which apply to specific questions, or issues you have like what test kits do I need to own, or what do I do when I have an ammonia spike. Reading the entire article will of course be flattering to the author, but will also put us back in the same situation that the cycle sticky is in.

Table of Contents:
What do we mean by cycling?
Ammonia (NH3)
Nitrite (NO2)
Nitrate (NO3)
Methods of cycling
Fishless cycling
Plant cycling
Fish cycling
Instructions on starting your cycle
How to fishless cycle
How to Plant Cycle
How to Fishy cycle
Short cuts and additional information
Bacteria starter colonies
Fishless cycling with bacteria starter
Fishy cycling with bacteria starter
Sources of bacteria
Existing established cycled tanks
Culture your own media
Other Products
Existing tank Water
What to do in the event of an ammonia spike?
What to do in the event of a Nitrite spike?
Other things to know and wonder about
Cloudy water
About Bacteria
What test kits should I buy and what if I don?t have them?
(Table of contents added by Reiverix)

What do we mean by cycling:
Nitrogen Cycle Diagram-diagram created and provided by aklaum
In our tanks, nitrogen is introduced, converted and hopefully removed. Ammonia is produced by fish, inverts, and bacteria constantly; it is converted by bacteria in a couple of stages until it becomes nitrate; and it is removed by plants or water changes. Different nitrogenous compounds have different effects on our fish and tank, most of which are toxic effects. We must establish ways to convert dangerous nitrogen compounds to reasonably benign compounds. Once those methods are established then we have ?built? a nitrogen cycle in our tank, and our fish are safe from the effects of dangerous nitrogen compounds.

The first compound produced is ammonia (NH3):
Ammonia or ammonium ion is excreted by fish, and is produced from pretty much all manner of decaying matter in our tanks. Ammonia in any detectable concentration is an irritant at minimum. In concentrations higher than roughly 0.25 ppm it will damage a fish?s gills. Exposure to more than trace levels of ammonia will leave permanent gill damage, which will hinder the fish?s ability to breathe for its entire lifespan. During exposure to ammonia, most fish will breathe rapidly, show inflamed or swollen gills, and move to the top of the tank where oxygen is more readily available. Some fish can handle this stress better than others, but in no case is a fish immune to the effects of ammonia. It damages all fish whether or not they are tough enough to survive the exposure.

The next nitrogen compound produced is nitrite (NO2):
Bacteria consume the ammonia, and the waste they produce is nitrite. Like ammonia, nitrite is highly toxic. It blocks the blood?s ability to absorb oxygen. This means even if your fish are able to breathe well, their muscles and organs will not get the oxygen needed to function properly. Fish exposed to measurable levels of nitrite will often act drunk, they will be lethargic, panicky, they will bump into things in the tank, and roll over and float aimlessly around. Once again there are hardy fish that can survive this exposure, but it is not a good practice to put fish through the experience. IME (In My Experience) fish which have been through a nitrite spike most often develop some type of secondary infection or illness within a day or two. The stress weakens them badly enough that their immune system will not respond to other attacks. Very few fish survive high nitrite spikes long term, even if they survive them short term.

The final nitrogen compound in the cycle is nitrate (NO3):

A second type of bacteria establishes itself to consume NitrIte it then produces waste in the form of Nitrate.
Nitrate by comparison to the first two is benign. Long-term exposure to high nitrate levels is hazardous to your fish?s health, but typical, reasonable levels of Nitrate are not harmful. Nitrate must be removed either via water changes or plant consumption. In most cases water changes are the solution, in planted tanks nitrate is consumed, but water changes are still typically needed to balance fertilizers and reduce other pollutants we cannot test for. So in a nutshell Water changes are almost always needed to keep your tank clean and healthy. Most people who understand the process well, target something between 10-40 ppm nitrate in their tanks. They establish a maintenance and feeding routine that keeps the levels where they want them, and keeps their fish healthy long term. There are occasional reasons to keep nitrates much lower, and vice versa, some of these will be covered later in the article so please read on.

Once all the converters are in place in large enough volumes, the tank is ?cycled?. We often hear the quote "My cycle is finished" Or "I'm done cycling". Technically the cycle is estabilished in the sytem, it is never done. It continues for the duration of the tanks lifespan. For general terminoligy, when someone says "their cyle is done" They are referring to the fact that the "cycle is done estabilishing in the tank"
As long as we do nothing to remove those bacteria and or plants, and we do nothing to significantly increase ammonia production then the tank will remain free of detectable ammonia and nitrite, and we can remove nitrate via water change as it builds up.

Methods of cycling

There are three basic methods of cycling that work well in this hobby. There are multiple variations and ways to perform each method. These will be covered in detail in their own section. This is just an overview of the basic methods and their advantages and disadvantages. All three are viable workable methods if done properly, all three can be done humanely if understood and done properly.

Fishless cycling:

Dr. Chris Cow is credited with the concept by most folks. I do not know for certain he was the pioneer, but if he wasn?t he was definitely one of the first to promote, organize, and test fishless cycling methods. His purpose was for beginners to have a better, easier, more humane method than the traditional fishy cycle, and it should be remembered as we discuss this that it was designed for beginners and not necessarily the experienced tank keeper with plenty of knowledge along with tanks to borrow things from. Also bear in mind that fundamentals always apply so while the concept is for beginners, the knowledge benefits everyone.
Dr. Chris Cow has two articles on fishless cycling posted at Aquasource. They can be read here:

And here:

There is a wealth of information out there on this method, if you wish to research just Google fishless cycling you?ll get plenty of reading material to choose from.

In a nutshell this incorporates any method where a source of ammonia other than live animals is used to start the biological processes. This method is widely accepted as the easiest most complete and most risk free method to cycle a tank. If there are no fish involved there is no risk of harming fish. It is that simple.

1.No risk to fish.
2.No forced work on the fish keeper, in other words no emergency water changes, or panic moments.
3.The bacteria colony established is very large so full stocking can be done immediately upon completion of the cycle.
4.If something goes amiss, there are still no fish in the tank.
5.While the tank is cycling, the hobbyist has time to decide on, find, reserve, and observe what fish they want. Most folks stock their first tank and learn later that they made poor stocking choices, or would have preferred a different scheme, Fishless cycling gives a period long enough to research ideas and curb impulse buying. This is a huge advantage that is seldom mentioned.

1.The tank is empty with no fish to look at while cycling.

Plant cycling (sometimes called the silent cycle):
This method is less widely known and understood than Fishless cycling, but is every bit as viable if certain conditions are met. It is not a method I would necessarily recommend to inexperienced plant keepers, but that makes it no less viable.
Ammonia is the easiest of the nitrogen compounds for plants to consume. Therefore it is the first form of nitrogen they will uptake when they are growing well. With this in mind, setting up a tank and filling it with healthy fast growing plants will provide a means for almost all ammonia to be consumed. If the ammonia is consumed by the plants then it will not build to toxic levels, and nitrite in turn will not be produced at toxic levels by ammonia eating bacteria.

The trace (unreadable levels) of ammonia that escape the plants will still allow the bacteria to establish in low levels, but essentially the plants are the bio-filter, and the bacteria colony remains very, very small.

1.Less chance for algae issues (these are covered later in the article) typical with cycling.
2.Plants are added immediately, and fish can be added fairly soon thereafter so you have something in the tank to stare at.

1. If plants are not or do not remain healthy, they decay and add to ammonia production.
2. It requires a certain amount of plant mass and usually certain types of plants to rapidly consume large quantities of ammonia so options are somewhat limited if you want to do this with plants you intend to keep.
3. For inexperienced plant keepers, there is a lot to know to keep most plants healthy.
4. If you don?t want a heavily planted tank this really is not the best option since you would have to secure lighting, fertilizer and so on and then would not need these items later.

Fish cycling.
This method is frowned upon by many people. There are a lot of ways to go about the process, and many of those methods are inhumane, risky, and poor practices in general. However a fishy cycle can be done without harming fish, and without being inhumane. It is a viable method if understood. Most of us who have been in the hobby for years have done many fishy cycles; some of us have done them without harming fish.
A properly done Fishy cycle is a tedious, labor intensive job, and leaves you with a drawn out stocking time frame that postpones the end result of a fully stocked healthy tank. Therefore even those of us who know full well how to do a fishy cycle will generally agree it isn?t the best method.

1. Some fish will be in the tank from the start so you don?t have to stare at an empty tank,
2. If you already bought your fish before you knew there was such a thing as a cycle, then this method can work and prevent disaster.

1. The risk factor is huge, ammonia and nitrite do not wait for you to get home from work before they spike, they do not care if you have plans for the evening either.
2. The workload is huge most of the time. If there is nothing in the tank that consumes ammonia and nitrite yet, then water changes are required to control those compounds. With a moderate to heavy stocking level, this may mean several water changes a day.
3. One hiccup, missed water change, or distraction and you still have injured fish no matter how hard you worked for the other 29-40 days while cycling.
4. If your goal of stocking does not include hardy fish, you stand a much higher risk of fish loss, or you have to deal with fish you didn?t want when the cycle is done.
5. Stressed fish succumb to disease quicker, so the chances are high of having additional complications to worry about in the middle of the cycle.

Many people recommend filling a tank with ?hardy, inexpensive? fish and letting nature take its course and if a few fish die, Oh well. This is not a viable recommendation ever in my mind. Purposefully killing (or even just harming) fish because someone is too lazy to do water changes and too impatient to wait out a fishless cycle goes against the grain of everything responsible in our hobby. Most people do this unknowingly the first time, but anyone who knows better and still does this is irresponsible at best. Additionally, since feeder fish are often recomended for this task. The possibility of disease transfer is very high. LFS feeder fish are often poorly housed and disease is common. Bringing home this high possibility of disease to your new tank makes little sense.
People who do not know better, and find themselves in the situation of a heavily stocked un-cycled tank, need to grin and bear it once they know. It?s not a crime to fill your tank with fish when you don?t know better, it is wrong to not even attempt to protect those fish once you do.

Now we know what each method entails, how do we start our cycle?

Instructions on starting your cycle:

How to fishless cycle:
Set-up your tank, add water and treat for Chlorine or chloramines if they apply.
Add ammonia to a level of 5ppm (amonia sources discussed later).
Since commercial ammonia products come in various concentrations, it?s hard to say how much exactly to dose to get your 5ppm. The best way to determine is to add a specified amount, test, add some more and test until you achieve the level you want. Record your amount so you have a ballpark figure to work with from there on.

It should also be noted that ammonia disperses immediately in water. It is not the effect of mixing two liquids, but rather the effect of a gas being absorbed into the water. Ammonia has a rapid absorption rate, and will spread evenly throughout the entire body of water. It does not settle, and it does not require mixing. If you dump ammonia into your tank, the time it takes to put the lid back on the bottle is more than enough to have it evenly mixed and ready to test.

Test for ammonia on a regular basis During the early stages. I recommend every 2-3 days at first. Once you start to see changing ammonia levels then begin daily testing.
When ammonia level begins to drop in the tank, dose additional ammonia to maintain a level of 3-5 ppm. Also, when ammonia begins to drop, start testing for nitrites. Once Nitrites start to climb, Then you are into the second stage of the cycle establishment. Nitrites should start showing up immediately when ammonia drops, but there are occasionally outside factors at work, so testing is the best way to know things are going well. Without a bacteria starter (see shortcuts below) colony this first part of the process takes 1-4 weeks. I?d like to narrow it down, but that?s reality. Be patient. The bacteria will find their way to the tank without any help.

When nitrites start showing, most folks recommend maintaining the ammonia level at 3 ppm. Nitrite eaters don?t really like high ammonia levels, but we want to continue growing and expanding our ammonia colony so we maintain a good dose somewhere in the readable range. We target 3 ppm but Exact levels are not critical. You will see different reccomendations made by different people. Don't fret if you are at 2 ppm instead of 3ppm. Keep the level below 5ppm to protect your nitrite eaters, and keep it high enough to measure. Anything in between will suffice to continue progress.

It should also be noted that at this point, once a day ammonia testing and dosing is adequate. Even if the ammonia drops below readable levels in one day?s time, once a day dosing will be enough ammonia to easily maintain your progress. If you dose each day to achieve 3 ppm then the bacteria will reduce that level by the next day. You do not need to overwork the ammonia dosing

Nitrites in most cases will climb right off the testing scale so relax and limit your testing to once every 2-3 days. Since you are actively adding and checking ammonia just consider that the nitrites will take care of themselves.
This is the slow (discouraging) part of the cycle. Your nitrites will typically appear unchanged for 7-14 days, and then suddenly they will drop and disappear.

At this point dose to 5ppm ammonia, wait 24hours and test your tank for both ammonia and nitrite. If both levels read 0 ppm after 24 hours, your cycle is established. At this point you nitrate levels will be very high. A water change of 90% give or take 9% should reduce the nitrates to a low level. The tank is then ready for a full bio-load, and you have had 4-6 weeks to decide on stocking, find the fish you want at the LFS, reserve and observe those fish and save up the coin to acquire them. Go get your fish and put them in the tank. And sleep well knowing that none of them were subjected to an ammonia spike or a nitrite spike while in your care. If it will be a few days until you can get the fish just keep feeding ammonia to the tank and plan to do another huge water change before you go to the store to get your fish.

Additional info for fishless cycling:

An ammonia source must be used. Thus the question of what ammonia is safe, and where do I get it?
The easiest cleanest method is clear or pure ammonia. Generic brands are great for this because they don?t always have the fun stuff added.
I use ?clear Ammonia? from Wal-mart. The ingredients are water, ammonia, and chelating agents. The chelaters are harmless.

The ingredients you want to avoid are surfactants, scents, or any ingredient with big hard to pronounce names (lol).
Many folks recommend shaking the bottle of ammonia, if it gets sudsy on top it should be avoided. There are about a million or so threads on the boards discussing different brand names and types of ammonia that people have successfully used. Take the time to make sure you have the right kind of ammonia. This linked thread will hopefully be organized into an ammonia buyer?s guide:

If you can?t find ammonia you trust then use some type of ammonia-producing waste. A couple of cocktail shrimp or some fish food will produce ammonia pretty well. However you cannot predict amounts when using this method so It is far less precise and useful than dosing exact amounts of ammonia. If you add too much waste, you get too high an ammonia titer; if you don?t add enough, you lose the advantage of being able to fully stock at the end of the cycle.

Additional thoughts info and pitfalls:

This thread covers much of what I?m about to write as well.

RTR also wrote an excellent article on new tank syndrome which can be found here:

The pH:
The biological processes used to convert nitrogen compounds eat up Carbonate hardness (KH). When KH is depleted pH crashes, I do not know (I?m sure someone does) if the acidic water kills the bacteria, or the lack of available carbon starves them, but I do know that a pH crash during a fishless cycle will stall or kill it off, and you will need to start over.
For hard water folks this usually isn?t an issue. For soft water folks it is. My tap water comes with a KH of 2-3 degrees and a pH of 7.6-7.8 In one week my KH would drop to 0dKH and pH to 6.8 if I did not supplement carbonate in some form. Had I not caught the drop, my tank would have fallen well below measurable pH ranges quite quickly and I would have killed my bacteria.

For more information on KH, see the chemistry article:

or search KH on the boards

For the quick fix without research (not my method of choice or recommendation), add 1 teaspoon of baking soda to 30 gallons of water to increase KH 1 degree. To roughly determine KH without a test kit (And I do mean rough) use this link:

Atmospheric co2 levels are 2-5 ppm depending on height above sea level and a couple million other factors. So assume 3 ppm Co2, use the chart at the bottom of that link to compare co2 to pH and derive KH. REMEMBER THIS IS A REALLY CRUDE WAY TO DETERMINE THINGS. Also Remember that you must age your tap water to get an accurate reading on pH. Place some water in a shallow conatainer overnight and let it"air out" before testing pH.
There are pitfalls to using guestimations rather than buying a KH test kit and knowing what you are working with. This will help until you get your test kit, but a KH test kit is something everyone should acquire.
In My opinion a KH of 4 dKH is minimum for fishless cycling. If your tap water contains that amount, water changes can be done to maintain it (see additional info below on water changes), if not baking soda is quick and effective, and since no fish are in the tank, you can add it as needed without worry of problems.

Tank temperature:
I do not know the ultimate livable range of our little microscopic friends, but I do know that adverse temperature has an effect and it is beneficial to make sure the tank doesn?t get too cold or hot. So with that in mind, you should install your heater and run it at normal tank temperature while cycling.


Do not turn on your lights during a fishless cycle. Plain and simple, algae eats ammonia also, and with lighting and ammonia at 5ppm you have created an algae production facility. You will learn much about algae control but who really wants the frustration.
More info covered below under the heading of Algae.

How to Plant Cycle:

In this method we are relying on plants to uptake virtually all available ammonia and thus eliminate the need for bacteria to convert it into safer substances.

The key here is high volume of healthy plants growing rapidly enough to utilize the nitrogen available.

The base instructions are simple.
Fill you tank (treat for chlorine and chloramines), add plants and lights, Give the plants a few days to week to ensure they are growing well and established (you will need to fertilize and provide for the needs of those plants)
Next add your fish. Most folks reccomend starting with algae eaters.
Add a few fish monitor to make sure things stay stable, then add more fish.
Keep the plants healthy and add additional needed fertilization to allow the plants to grow and consume all ammonia.
When using this method, the bacteria will still establish, but do so in small numbers. If you were to remove all plants, and leave the fish you would definitely see ammonia and nitrite spikes. You are relying on the plant mass completely to keep your fish safe. This is a great method, but you really need to know what you are doing with plants to avoid risk.
If you do wish to remove plants, it should be done slowly over a period of several weeks to allow the bio-filter to grow according to the changes.

Plants that work well:
Any fast growing stem or nutrient hog type of plant will do a good job for you in this method. My favorite happens to be Anacharis, which is by all standards a ?weed? as long as it has adequate light, it will scarf up all of the nitrogen it can. Anacharis is not picky about fertilizer balance or even CO2 levels in my experience so it is a great utility plant for this type of project
On the same note, run a search for algae busters, nutrient hogs, or fast growers and you?ll come up with a lot of plant options that could be used. There still IMO needs to be enough knowledge to keep plants growing healthy and rapidly, or disaster will strike.

Other pitfalls:

Algae, once again I will refer you to the Algae section below, but plants light and ammonia create a setting ripe for algae. Plants can and will out compete algae, but if anything is amiss the green water shall surely appear.

Dying plants:
If after you add your plants and fish you find out you can?t get the plants to grow well, you are now into a fishy cycle with the added problem of decaying plant matter in the tank furthering the complications. Make the best of it. Remove all obviously dead material, do whatever water changes it takes to keep nitrogen levels in check, and work on perking up you plants. If you can?t get the plants you have to grow I do not recommend going out and getting a bunch more plants. Figure out what the plant issue is first, then supplement the tank with more plants after you know they will grow and help you. Remember when choosing plants that many plants are grown emersed and the leaves will die off and new leaves start up. Additionally plants like crypts and vals will die off for spite and then return later. Not a big issue most times, but when using the plants to cycle these plants are not good choices.

Too much to worry about:
This is a personal pet peeve of mine I guess you could say, and not at all a scientific argument.
When people are new to the hobby, there is so much to learn, so many mistakes to be made, and so many tasks to accomplish that adding to the confusion is never in my opinion a good thing. If you are trying to learn about fish, and trying to cycle a tank. Trying to learn about plants simultaneously can be overwhelming. You need to know about lights fertilizers CO2, substrates etc. Yes you can shortcut a lot of things, but you can also turn great ideas into disasters and this hobby has lost many people over one disaster. Don?t set yourself up for failure.
Plants are awesome, I keep them, I love them, and I recommend them. Taken step by step they are not highly difficult or frustrating but there is much to know. IF you are new in the hobby, get your tank cycled, get your fish safely swimming around, then get your plants and continue to learn. That is why I do not recommend plant cycling for beginners. For anyone who knows their way around planted tanks I would highly recommend this method.

Temperature and lighting are, of course, dictated by the plants and fish, so there is not a lot of need for discussion here. If you have specific questions on temp and lights browse the plant forum or search the web. There is a wealth of information on plants available.

How to Fishy cycle:
This method can be done in several ways, some are fine, others are not. The concept in it?s correct form is to set-up your tank, add a few small hardy fish, monitor ammonia and nitrite levels, do necessary water changes to prevent damage to your fish, and when the cycle is established then you add 1 or two small fish, test numbers for a few days (usually a week), and then add one or two more fish. So on and so forth until the full amount of planned stocking is achieved.
If you have a big enough tank and a small enough fish to start with you will not even see measurable amounts of ammonia and nitrite. The cycle is still starting and growing, but the levels of waste produced are not spiking high enough for detection. This is a good thing and does not delay the process. Eventually nitrates will show up and you will know the bacteria are there - BUT your bacteria colony is established only to handle the bio-load in the tank. So you have to increase bio-load very slowly and carefully to prevent spikes. Add a fish, give it time; add another, give it time. To heavily stock a 55g with smallish community fish can take quite a while. Of course as you get more and more fish you can add quicker. Think of this in percentages. Two tetras in a cycled tank and you add 2 more you have doubled the bio-load, then when you add 2 more again you have added 50% and so on. Don?t get too aggressive though, you will end up harming fish or doing water changes far too often.

Even when doing this in the most conservative manner daily testing is a must to ensure the safety of your fish. In my personal opinion, 0.5 ppm ammonia is the maximum allowable level. 0.25 ppm ammonia should be considered a serious concern. 0.5ppm nitrite is also the maximum for me. So if you cycle with fish plan to test a lot (tedious) and plan to do water changes each and every time the liquid in the test kits changes color. This is the downfall of the fishy cycle; you need to do water changes whenever your tank requires it, not when it fits your schedule. You need to do however much water changing it takes to protect your fish no matter how tired of water changing you become. You need to test a couple of times a day even if you are being conservative.

For those who already own their fish when they find out the bad news, just test and do water changes, endure the chores for 4-6 weeks, and learn from the experience. Some of the better members on these boards started here with an ?I just bought 12 fish and four of them died? thread. They did what it took and came out of it with a lot of knowledge experience and information.

Temperature is dictated by the needs of the fish you wish to keep

Lighting: Fishy cycling does tend to result in fewer green water blooms than fishless cycling. The fish bring in the bacteria with them, and the ammonia levels don't go as high as seen in Fishless cycling. However, it still happens often enough to be a concern. Additionally your fish (In most cases) prefer shade and darkness, so its never a bad idea to leave the lights out when cycling via this method. It will help reduce the chance of green water, and additionally the shaded tank will help the fish stay calm in their new environment. As always people like to look at their new fish, and light is helpful in doing this. Just turn the lights on when you want to observe and leave them off otherwise.

Short cuts and additional information

Bacteria starter colonies:
About two thirds of the people reading this are ready to scream because this hasn?t been mentioned yet, so I thought I should put this one first.
Since the goal is to establish enough bacteria to handle our respective bio loads, borrowing, stealing, or buying bacteria should always be done if possible. This method applies to both fishy and fishless, but is far superior when used for fishless because as always fishless is less risky. Bacteria starter colonies come from many places all of which are discussed below under the heading ?sources of bacteria? as well as some tips on how to not murder your bacteria before adding it to the tank.
When using bacteria starter colonies, we essentially add already living bacteria at the same time we add our ammonia source. Assuming we didn?t kill the bacteria before we added it, and assuming we added enough to handle our bio-load, then we literally have established the cycle instantly.
This does not change the fact that you are either doing a fishy or fishless cycle, it only shortcuts the process by jump starting your bacteria colonies.

Now there was a lot of assuming going on there so lets be more specific on ideal methods.
Fishless cycling with bacteria colonies:
We add our bacteria, add our ammonia source, and test 24 hours later. If we have 0 ammonia, 0 nitrites and measurable nitrates then our tank is ready for a full bio-load. It never hurts to re-dose our ammonia and give it another 24 hours to be sure.

If we have some ammonia left and measurable nitrites, then we didn?t add enough bacteria for the full load of ammonia, but we have cut at least a couple of weeks out of our fishless cycle, so pick it up at that point. Dose the ammonia up to the desired level, monitor and continue.

If there were no changes in ammonia, no nitrites appeared, and no nitrates appeared then we either added very little bacteria, or we killed our bacteria getting it to the tank. Give it a couple of days and watch for nitrites. Once again wherever you end up, there you are. Continue from that point with the fishless cycle instructions.

Multiple bacteria doses:
O.K. we dosed bacteria, added our ammonia and did not get whatever result we wanted. If we still want to speed things up all we have to do is add more bacteria. In a lot of cases, when using high doses of ammonia, the nitrite eaters will not survive due to a combination of lack of food and ammonia levels. It should be stressed that a second dose about 7 (give or take) days after you start the cycle should be planned on to re-boost the nitrite part of the cycle. Don?t assume that adding it once will shortcut both colonies completely.

Fishy cycling with bacteria starter:
The same principles apply really, the difference is pretty straightforward. If you happen to buy borrow or steal a batch of bacteria that doesn?t get to your tank alive, then you have a fishy cycle on your hands, and will need to monitor the tank, and do water changes; monitor the tank and do water changes (Yes I typed that twice, it repeats until the end of the cycle).
It is also difficult to know without trial and error experience how much bacteria to add for how many fish. So you either overkill the bacteria and under kill the bio-load which leaves you stocking slowly again, or you risk mini-cycles because you didn?t have enough bacteria to handle the bio-load you added. Just for the record, your fish?s gills don?t know the difference between a mini cycle and the other kind.
With this method, if anything goes wrong, additional bacteria dosing can help bail you out quickly. If you fishy cycle with bacteria starter colonies, plan on dosing several times. Anything planned on is easier to do, and if it works the first round great. If not you are prepared.

Sources of bacteria:

1.Existing established cycled tanks.
This is the easiest most consistant way to get things rolling. But there needs to be an understanding of what bacteria require in order to help us find the best sources. Bacteria?s primary requirements are food (their respective nitrogen compound), oxygen, and a surface area to cling too. So high surface area, high flow parts of the tank are the best place for a colony to grow. This makes the filter media king of all bacteria growers. A borrowed sponge, or better yet borrowed bio-media of some sort will have as large of a colony as is capable of growing in a system. Usually the upper levels of the substrate are second. In the substrate, oxygen is the limiting factor, due to being low in the tank, and receiving less circulation than the filter areas. Once you get below the crust of the substrate, oxygen is severely limited. So if borrowing gravel, try to skim it from the surface for the greatest benefit.
Of course in tanks With UGF or RFUG filtration the entire substrate bed is a highly oxygenated highly circulated bio-filter, so any gravel from a UGF tank should be viewed as bio-media with excellent colonies.

Every surface in the tank that has water flow will have bacteria, but things such as plant leaves, and plastic d?cor, or large smooth rocks do not have much surface area, while more porous items like lava rock, gravel, and sponges have huge amounts of surface area. Pick things that will get you the biggest colony. But always remember that some bacteria are better than no bacteria so go with the best you can and be patient while the rest grow. The gunk rinsed out of most filters is a surface area also, so even just squeezing all of the nastiness out of someone else?s sponges and dumping it in you tank will give you a starter colony.

When we borrow media of any type, remember the requirements. Keep the media wet in tank water, keep it in water that has some o2 and keep it at something near tank temperatures. Temperature does not need to be exact, but excessive heat (parked car in the summer) or excessive cold (parked car in the winter) could kill your bacteria. The less time it spends in a bag outside of a tank the better. If it must be kept out of a tank all day, swish the water now and then to oxygenate it a little. Bacteria are actually fairly resilient, but there is no need to abuse your colony so take a few precautions.

How do I use the media I brought home:
It is really simple to use your borrowed colony, if it is gravel, rock wool, or media. Bag it in a mesh bag of some type (I use my wife?s discarded nylons) and hang it in the tank in an area of good flow and good O2, ideally near the filter intake, or inside the filter itself. For items like lava rock they can just be placed in the tank, as they are easy to remove later. The same with bio-wheels, bio-balls, etc. Just get it in the tank, and put it where it will receive decent flow and oxygen and let it spread and grow. If you use filter squeezings, dump them in your filter, or in your tank near the filter intake. Yeah they make a mess temporarily, but in the big picture that amounts to a whoopity doo.

One downside is the possibility of disease transfer from one system to another. Make sure you trust the source of the media; if not, patience is probably the better option.

An additional cautionary thought is: do not remove too much bacteria from an existing tank. You can throw the donor tank into a mini cycle as well.
For instance if the primary bio-filter on that tank is a bio-wheel and you take it away, it may be enough to cause problems. However, borrowing the filter cartridge from that tank while leaving the bio-wheel will give you a great starter colony without jeopardizing the donor tank. How much is too much depends on the size of the donor tank, filtration on the donor tank, and most importantly the bio-load of the donor tank. For more detail see the heading below entitled ?About Bacteria?
2.Culture your own media.
This essentially is the same or equivalent process as borrowing, buying, and stealing, but I thought it wise to add a blurb on this. It is quite easy to go ahead and prepare yourself a culture if you have another tank at your disposal. Buy your filter first. Install it on another tank and run it for several days. Or buy some bio-balls and float them in another tank. You can use almost anything that constitutes porous media placed in an active tank. If you have friends who own tanks, ask them if they mind hanging something in the tank for a week. There is one LFS here in Columbus Ohio that keeps bio-balls floating in all of their tanks. They recommend x number of bio-balls be purchased for x number of gallons of water. They then recommend those bio-balls go in the tank when fish are added and stay there for a month. They charge a nominal price per bio-ball. And they save an extreme amount of money in livestock guarantees with this approach. Most of their customers have no clue what the bio-balls do for them, but they know their fish don?t die 4 or 5 days after they take them home. Since bio-balls float and are reasonably clean, it is a great practice. Don?t be hesitant to build yourself a good culture while bringing home your new tank and getting it level and filled with gravel and water.

3. Bio-Spira.
I have not used this product, but have heard plenty of good things about it.
It has a couple of issues that should be discussed: the first is transport and storage. This product needs to be kept refrigerated from what I understand, and it needs to be used while still reasonably fresh. In other words if it is still good and alive it works well, if it isn?t it won?t work. When you buy the product and bring it home, you will not know until you use it if it is good. So in my opinion, it is better to use Bio-Spira with the fishless cycling method. Then if you got a bad batch, you are not suddenly the heir of a fishy cycle. As with other methods, a second dose several days into things will often help. The need for this can be determined with your test kits. If nitrites build and don?t go away, then you dose the Bio-Spira a second time.
4.Other Products:
?Cycle?, snake oil, Georges bacteria in a bottle etc. etc. there
are several other products out there claiming to be beneficial bacteria starters. To the best of my knowledge none of them stand up to scrutiny. These products sometimes contain bacteria that will eat ammonia, but it is not the same critters that will live in our systems long term. When these bacteria die, they typically add to the bio-load already there and complicate things a bunch. As a general rule all products except Bio-Spira are regarded as pollution in a bottle. Save your money. When new products come out, they will be tested, and we can add them to the good or bad side of this chapter.

5. Existing tank Water:
Many people suggest using water from an existing tank for a bacteria starter. Our bacteria are not free swimmers, and therefore adding water only will do very little to help our cycle. There just isn?t enough bacteria swimming from point a to point b at any given time to gain much by transfer of water. With that in mind, it is essentially a waste of effort to use tank water for a starter colony.

6. Plants:
There is some confusion about this idea. First of all lets just say that if you add live plants, you have dictated a need for the lights to be on. This is not a good scenario in the algae control sense. So if you are cycling for the establishment of a bacteria colony (anything but a plant cycle) then hold off on the plants until the bacterial cycle is done. Plants themselves are not a porous material and therefore not a great source of bacteria. HOWEVER, The rock wool that most commercial plants are potted in is a great source of bacteria. Most plants are grown emersed not submerse, in hydroponics facilities with good levels of nitrogen in the water for fertilization. The bacteria colonies are huge in hydroponics tracks, and rock wool is porous. If you can?t find other sources, buy some cheap potted plants, and use the rock wool potting material for your starter colony. It works very well. Either give the plant to friend, find a bucket to keep it in with light, or simply chuck it and consider the investment a purchase of bacteria. Many potted plants are far less expensive than Bio-Spira (just a hint)

What to do in the event of an ammonia spike:

As discussed earlier, ammonia burns the gills of your fish. The obvious answer is do not expose your fish to an ammonia spike, however that answer does nothing for the hobbyists who is testing for ammonia and finds readable levels in their tank with fish in it. So there are a couple of things that will help. The first, foremost, and best is water changes. Do however many and how big it takes to reduce the level. Another great product is Prime (dechlorinator made by Seachem). It binds ammonia into ammonium which is not harmful to fish. Ammonium is still available as a food source for your bacteria, so using Prime will not hurt the cycle but will help reduce the damage to the fish. I believe Amquel-plus also binds ammonia, most other dechlorinators don?t stand up to scrutiny in this regard, so do not believe everything you read on the labels.

What to do in the event of a Nitrite spike:
As with ammonia, water changes are the best quickest way to reduce levels and protect your fish. Additionally the chloride ion blocks the effects of nitrite to some degree. Dosing the tank with some form of chloride will help alleviate the stress to your fish, and help them get through the nitrite spike. Commonly used forms of chloride are NaCl (table salt/ sodium chloride), KCl (nu-salt/ potassium chloride), and CaCl (ice melter/ calcium chloride). It does not take a lot of Cl to help from what I understand. I have seen dosage recommendations as low as ? teaspoon of compound per gallon given. I personally would go with ? teaspoon per gallon, keeping in mind that water changes will reduce the total levels, so you should dose your replacement water when doing water changes. Of course if your get the nitrites under control, you won?t need the Cl in the tank.

Other things to know and wonder about


Algae have been mentioned several times thus far. It is a common problem we see in new tanks. Specifically, green water blooms from tiny free floating algae.
This issue can and will apply to all methods of cycling, however the high ammonia titers of fishless cycling make it far more prone to green water blooms than other methods.
Ammonia is algae food just like it is plant food, combine this with light and limited amounts of bacteria in the tank and the green water starts. Green water typically cannot be removed via water changes. Once it?s there it just wants to grow and grow and grow. We do a water change and within a day or two it?s as bad as ever, so we do a lot of water changes and then take a break and it?s as bad as ever. We ponder nuclear weapons, but there is a fear of glow in the dark fish with big teeth so we scrap that idea.

There are some simple solutions that do not involve uranium.
The first is the blackout. Blackouts are free, they cost nothing, and they are easy on the budget as well. All that is needed is complete blockage of all light for 3-4 days. Your fish don?t care, your bacteria don't care, and if you have plants they won?t care either. Plants store nutrients, simple algae does not (some more complex algae will survive blackouts, but not green water) Take away the light for an extended period and the algae dies while the plants survive it.
The key is that all light must be blocked out. Even the smallest amount of light will allow some of the algae to live and it will return with a vengeance. I use newspaper taped all the way around and over my tank in multiple layers. Some folks recommend black plastic trash bags, blankets and or cardboard. Pick you method, make sure you cover everything. For people with Aquaclear filters remember they are translucent and must be blacked out as well.

Do a water change at the start of the blackout, and if the bloom was very thick do one halfway through the blackout period. At the end of your 3+ days you will uncover a crystal clear tank and rejoice in your success. At the end of the blackout, do a water change and rinse you media to remove the dead algae

The next method often suggested is UV sterilizers. If you already own one it?s a great option, if you don?t they are expensive and have limited use on freshwater tanks. (Oh? And did I mention Blackouts are free?) UV sterilizers will kill the algae. Istall and run the sterilizer, and let the Uv bulb do it's thing.

Diatom and micron filters. Both are capable of collecting the algae from the water and if run for a few days will most likely capture it all and eliminate the problem. When using any mechanical method to capture tiny particles like this, there is a need to frequently change media. Since algae blooms should be a short-term need, if you have a diatom or micron filter use it, if you don?t they are far more expensive than a blackout.

Algaecides: I do not personally promote algaecides or think it?s wise to use them. Most of them kill algae; they also kill plants (and invertebrates) and contribute to general pollution levels. In many cases algeacides contain Copper in some form. In no way do I ever reccomend copper be used in a fish tank.

No matter what method you use. Remove the dead algae from the system via water changes or media cleaning. Dead plant material produces ammonia which in turn feeds algae. If the underlying problem is not rectified, killing the algae will give temporary results. In new tanks the ammonia levels create the algae blooms. In many cases with new tanks the algea does not return once it is killed off. If you have repeat problems, you have a maintenance issue and the algae will continue until that issue is found and corrected

Cloudy water:
Many folks complain of cloudy water during the early stages of fishless cycling. It is common to have bacteria blooms in your tank and they generally clear themselves up pretty rapidly. If you get cloudy water, put a bit in a jar and hold it against a white piece of paper. Green algae blooms will look white in your tank until they grow thick. Against a white sheet of paper the green can be seen and the cloudiness identified. If the cloudiness is not green against a sheet of white paper then you are most likely dealing with a bacterial bloom. ride it out, and as said it will genrally clear itself.
There are a lot of processes going on aside from the nitrifying bacteria in any new tank. Full details additional information and several excellent links can be found here:

Read this article to get a better understanding of why your water may or may not get cloudy in your new tank.

About Bacteria:

There is much confusion about bacteria and how it grows lives and functions; there is also a whole gambit of myths surrounding the bacteria based on false assumptions and misinformation. The bacteria we want are fairly slow growing by bacterial standards. The amount of ammonia added will not speed up the cycle time in relative terms. One small fish in a 55g tank will cycle that tank at the same speed as 5ppm of ammonia will. The difference is the size of the colony created in the end. The bacteria multiply until available food stops them. since multiplication is exponential, the cycle estabilishes at almost exactly the same speed regrdless of ammonia levels. So for general purposes a fishless cycle at 5ppm will create a bigger colony, but it still takes as long to create. If we wanted to really split hairs we could say that the higher ammonia levels slow things slightly because the bacteria has to split a few extra times to compensate. But the difference is a matter of a few hours not several days.
Here is a great thread on this subject:

More ammonia will not speed up the cycle for you. It takes four to eight weeks no matter what for bacteria to establish from scratch and grow to a respectable colony size. The reason for the high titer of ammonia in fishless cycling is to establish a colony more than large enough to handle the full bio-load of the tank at the end of the cycle. This allows you to fully stock the tank at one time.

In an established tank, there are theoretically the maximum number of bacteria that ammonia, surface area, and O2 will support. So when we borrow media from another tank, while we do deplete the colony in most cases the remaining bacteria have plenty of appetite to still handle the bio-load. So if we borrow half of the bio-filter (theoretical numbers) then each remaining bacteria gets twice as much to eat that day. This will also encourage each bacterium to reproduce and in the time it takes for one bacteria reproduction cycle, the original colony size is matched.
Obviously the process is quite a bit more complex in reality, but it is not difficult to borrow large amounts of bio-media without hurting the donor tank. Just remember the three basic requirements: Oxygen, food, and a surface to cling to. Leave a significant colony, and take a significant colony.

What test kits should I buy and what if I don?t have them:
First of all let?s just say that there are investments in this hobby that are necessary. Test kits are one of those investments. I consider them as important as lights, filters, and water. Many people don?t know what they need, didn?t realize they needed them, or do not understand the significance of test kits. They need to plan on getting their own kits as soon as feasibly possible. Until then, they need to take water samples to their LFS and ask for a test so they know what is going on. Here are the basics on test kits, and my personal views on why or why not to own them. Take it for what it is worth, but test kits are worth the money every time for me.
I do not like, do not promote, and do not endorse the use of dip strips for testing. I find them inaccurate at best, which defeats the entire purpose of having a test. I have heard from very few satisfied user, and have heard over and over about problems related to poor test numbers from dip strips. In My Humble Opinion, Dip strips are worse than guessing randomly at numbers. I?d rather have a roulette wheel determining my parameters than use a dip strip. Take that for what it is worth, if you?ve had good luck with strip tests I?m happy for you. My money will always be spent on liquid tests.
After that glowing endorsement, I will say that most affordable hobby tests have some margin of error; these are not lab grade highly specific tests. If they are consistent and reasonably accurate then they suffice for our purposes. If you question the accuracy of your test at home, take a water sample to your LFS and compare their results to yours. It is easy and free to verify the accuracy of your home test.

Ammonia: An ammonia test kit is a must when cycling. If fishless cycling ammonia needs to be monitored at least once every 2-3 days, and dosages added according to levels. Without a test kit it?s a shot in the dark. Buy an ammonia kit. After the cycle is complete, any time you observe a problem in the tank, ammonia should be tested. It?s a basic fundamental water parameter, which should be verified when investigating problems. Be acutely aware that some ammonia tests do not distinguish between ammonia and ammonium. There are a lot of threads that address this. I believe that the general rule is if the test has two bottle of reagent then it will separate ammonia and ammonium, if it only has one bottle it will indicate both as one substance. Essentially what this means is that you could have perfectly safe water, and still read high ammonia if you have ammonium in that water and use the wrong kit. Any detectable levels of ammonia, no matter the form, is undesirable and indicates that your tank is not cycled, so ultimately knowing the speciation is academic (Last sentence contributed by Happychem)

Nitrite: essentially the same as ammonia, it needs to be monitored during the cycle, and should be tested for whenever there is a problem later.

Nitrate: As far as cycling, nitrates indicate the completion of the second stage, so a nitrate test helps in ensuring the cycle is done. Without knowing we have nitrates we cannot be 100% sure we finished our cycle. Additionally, I consider this the handiest kit I have. Nitrate is the number we use to monitor our pollution build-up in our tanks. If we keep nitrates low via water changes then we are keeping other pollutants low. I use my nitrate test to establish and monitor my maintenance schedule. I observe changes in nitrate levels, and over time I figure out how much water I need to change how often in a given tank to keep things in balance. Once I establish that maintenance routine then periodic testing is done to ensure no changes are needed in the routine.

"pH": The pH is a highly misunderstood parameter. Fish do not read pH. The term pH shock is a misnomer, but that is all subject for another article. The pH is an indicator of processes developing in our tank, and therefore a pH kit is handy to have. If I had to chose between buying a pH kit and buying a nitrate kit I personally would go with nitrate. But I do own and use both.

KH (Carbonate Hardness): From a cycle standpoint this is needed for soft water folks to monitor and guard against pH crashes. I consider this more important than a pH kit. pH is a result of alkalis and acids in our water. The natural buffer is Carbonate hardness or KH. Without knowing pH, I can set up and run a stable tank if I know KH. Furthermore, I can guard against crashes, calculate co2 and monitor tank changes based on this number. KH needs to be understood to be useful, but it really is a great number to know at any given time in your tank. For more information I refer you to the water chemistry article here at AC.

Since my numbers listed are posted in dKH (degrees of KH) it should be noted that there is 17.9 ppm per degree. This conversion applies to both KH and the below mentioned GH. 1 ppm and 1 mg/L are the same thing.

GH (General Hardness): From a cycling standpoint this isn?t a hugely necessary kit, it does however come in handy in tank keeping so it?s not a bad choice to own a GH kit.

Po4 (Phosphate): Phosphate is one of the macro nutrients needed for Plant growth. A Po4 test kit is a must have for plant keepers. For fish only tanks, the primary concern with Po4 is that it contributes to algae growth. It is always handy to know your Po4 level, but not as necessary in fish only tanks.

Myths:This is always my favorite section in any article I write. If someone could wave their magic wand and eliminate all aquarium myths at once, the boards would look like a ghost town. So when I have the opportunity to post the myths and de-bunk them I get giddy (please don?t try to picture a 6?11? 450 pound man sitting in the basement being giddy) Myths are the biggest difficulty any new hobbyists faces.

Myth #1: Water changes slow the cycle.
Since the bacteria we want arent free swimming and the amount of ammonia doesn?t have an effect on how fast the cycle completes, water changes cannot, do not, and will not slow the cycle. With fishless cycling there is seldom a need to do a water change; but if there is, do one, it won?t hurt anything. With fishy cycling there is often a need to do a water change, so do however many you need to, it won?t hurt anything.
Of course with any water change, add dechlorinator, and keep the temp steady just like you would for your fish at any other time. Chlorine will kill bacteria, but water changing will not.

Myth #2: Urinating in the tank is a good way to add ammonia.
This is definitely the best one from an entertainment value, but we get this question on occasion from a sincere person who wants to know. And occasionally we hear of someone handing out advice about this method as a good practice.
Urine contains urea which can and will contain ammonia. It also contains a lot of other stuff you don?t really want in your tank. There are a couple of threads covering details and arguments on the subject. Run a search on urinating and get a good chuckle. For those of you tall enough to pee in your tank please refrain from doing so. There are far better ways to accomplish what you need.

Myth # 3: Vacuuming and rinsing will wash away your bacteria.
This is simply not true, bacteria do not wash away that easy, if they did the fluidized bed filter would not work (We?ll give credit to RTR for that statement). I don?t recommend running your filter media under tap water (remember chlorine) I don?t recommend dipping your media in hot water, but if you need to vacuum gravel, rinse d?cor, or rinse media during you cycle process do so. Rinse items in a bucket of siphoned tank water and then put them back in the tank. The bacteria will still be there. High flow areas still grow bacteria, and cleaned items still house it.

Myth #4: Nitrosomas and Nitrobacter are the bacteria we are dealing with.
For some considerable time in this hobby that was the belief, it has been proven that these are not our critters. It really doesn?t matter except that Nitrosomas and Nitrobacter live under different conditions, Such as Freshwater verses Saltwater, or Soil/sewage verses Freshwater. People with access to those bacteria will not get good results using them. I sometimes believe that this myth is one of the reasons some bacteria in a bottle products don?t work. I know that the product Cycle does in fact contain a bacterium that eats ammonia, I also know that ?Cycle? does not contain the correct type of bacteria for our systems and therefore it dies and leaves us needing to do water changes.

Myth #5: Ammonia reducers are helpful.
This myth applies to ammo chips, ammonia reducing resins and pillows, and so on. These items chemically filter the ammonia out of the water, which stands to starve the bio-filter we need to establish. As with any chemical filter, these items ?fill up? and then cannot do their job. This puts our tank into an up and down cycle with ammonia and the resulting nitrite. Ammonia removers will not replace the bio-filter, and since they interfere somewhat with the establishment of the bio-filter, they are better off avoided.

Myth #6: Ammonia binding products like ?prime? hurt your cycle.
Unlike ammonia chips and resins which adsorb the ammonia from the water. Products like prime and Amquel-plus bind ammonia into the less harmful ion ammonium. This bound ammonium is still available for your bacteria to consume, but will not harm your fish. So using a product like Prime or Amquel-plus w
« Last Edit: September 14, 2006, 05:31:39 PM by JP » Logged
« Reply #1 on: August 29, 2006, 06:00:22 PM »

One small fish in a 55g tank will cycle that tank at the same speed as 5ppm of ammonia will. The difference is the size of the colony created in the end. The bacteria multiply until available food stops them. since multiplication is exponential, the cycle estabilishes at almost exactly the same speed regrdless of ammonia levels. So for general purposes a fishless cycle at 5ppm will create a bigger colony, but it still takes as long to create. If we wanted to really split hairs we could say that the higher ammonia levels slow things slightly because the bacteria has to split a few extra times to compensate. But the difference is a matter of a few hours not several days.

It is also difficult to know without trial and error experience how much bacteria to add for how many fish. So you either overkill the bacteria and under kill the bio-load which leaves you stocking slowly again, or you risk mini-cycles because you didn?t have enough bacteria to handle the bio-load you added.

Those two statements seem contradictory to me.  Some Googling leads me to believe most bacteria generation times fall between 20 minutes and 24 hours.  That fits the first paragraph - a few hours to double a biofilter.  So where do mini-cycles come from?  If you suddenly double the bioload, within a day, shouldn't the biofilter be ready to handle the load anyway?
« Reply #2 on: August 29, 2006, 08:44:25 PM »

The bacteria in qustion are extremely slow at reproducing by bacterial standards, But it's still only a matter of hours if I understand it correctly. Even very short exposure to ammonia or nitrite either one is damaging to fish. most mini cycles last less than 24 hours and still harm or even kill fish. It would not take 24 hours for the colony size to double, but the fish still feel the effects. In the case of fishless cycling at high ammonia titers, as said there will be a very slight delay in reaching full colony size as compared to fishy cycling with a few small fish.

I have seen ammonia and nitrite spikes go past 4ppm and back to 0 in a matter of 2-3 hours in tanks. The fish did not all recover despite the speed at which the bacteria compensated.

One would ahve to set up two tanks side by side to really see any difference, and more importantly since you have to stock slowly after a fishy cycle, the fishless tank will be ready for full stocking much sooner.
Whoa. Where did I put all my stuff?
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I know where rasaqua's stuff is.....

« Reply #3 on: August 29, 2006, 08:51:22 PM »

**Dave got a post in while I was composing this one. I really have to put it in supergear one of these times  biggrin **

Bacteria responsible for the conversion of ammonia to nitrite actually multiply at a slightly quicker rate than those that convert nitrites to nitrates.  The nitrifyers responsible for the nitrite conversion will also be hindered by any ammonia present in the system that can not be quickly scavenged.

There can be several 'cycles' taking place inside your aquarium besides the nitrogen cycle. Sulfur cycle, phosphorus cycle, carbon cycle, etc.. Here is one that also impacts ammonia production....The composition of protein molecules includes a great deal of nitrogen, hydrogen, carbon, and oxygen.  When protein molecules break down, nitrogen and hydrogen are linked together to form ammonia, (NH3). Living animals release the nitrogen of metabolic waste in the form of urea, uric acid, or, in the case of many aquatic animals, directly as ammonia.  "Decay" bacteria, (heterotrophic), use any available 'organic compounds' - urea, proteins, amino acids, fats, and carbohydrates, as energy sources to fuel their own existence.

As they remove the energy tied up in the chemical bonds of these organics, they break them  down into simpler and simpler compounds until they are finally just simple inorganic minerals.  This process is termed 'mineralization'.  Thus, ammonia, the toxic waste product of the metabolic processes of animals, and a major end-product of mineralization, is released in large quantity into the aquatic environment.
This process inforces the 'plant cycling method' that Dave mentioned above and the cautions waranted regarding the extra care needed for the plants during a plant cycling.

I seem to remember (which amounts to sorting through the Rolodex between my shoulders) reading that nitrosomonas bacteria can favorably double their numbers in approx. 20-24 hours, while Nitropsira bacteria do it in about 30 - 32 hours. If this were to occur within just a few hours (during an initial tank break-in), established theories would be blown out of the water and everthing inexperienced X-Mart or X-Co associates have been telling folks about purchasing both tank and fish at the same time would then become doctrine.  uhoh

When the nitrifying colony has already established in favorable locations in sufficient numbers to handle the present bio load (through water flow within filter bio media and other areas that deliver food, O2, and transfer wastes away) conversion is almost instantaneous. The colony will then be able to 'adjust' (reproduce) as long as there are favorable resources for them to do so. However, even though one can 'overdevelope' a bio colony during a fishless break-in, it can not get overdeveloped in an established tank. This is because in a fishless break-in (cycle) you are only adding ammonia, which is one compound, targeting the specific bacteria species we most want to promote. In an established tank with many cycles taking place at the same time, compounds are also being shunted into those other cycles.  Smiley


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« Reply #4 on: March 18, 2012, 06:27:52 PM »

Good! Was nice to read this:P
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