Badman's Tropical Fish

All-Water Boards => Beginner's Circle => Topic started by: h4nd on April 13, 2008, 10:22:11 AM

Title: Why don't we use Protein Skimmer in freshwater tank?
Post by: h4nd on April 13, 2008, 10:22:11 AM

I have Marine Tank and Freshwater tank. In marine tank, I use a Protein Skimmer to maintain the water quality (beside filter). I also use Live Rock as a place for bacteria to convert ammonia-nitrite-nitrate. I use sump too.

My question is:

Could any of you tell me, why don't we use protein skimmer in freshwater tank too?
I mean, Protein skimmer is definitely a good equipment to handle Dissolve Organics Compound BEFORE they turn into ammonia.

In marine tank, we also use SUMP. Why don't we use sump too in freshwater?

I have unused protein skimmer and empty tank, and I want to try to use it in my freshwater tank (before the filter). Do you think they (protein skimmer+sump) will be useful to help me provide the best water quality for my fish?

BTW, sorry for my english. English is not my mother tongue

Thank you

Title: Re: Why don't we use Protein Skimmer in freshwater tank?
Post by: RTR...Grumpy Ole Fogie on April 13, 2008, 10:57:13 AM
We do use lots of sumps in FW, at least some of us do.  It is is just a technique, and applies in fresh, brackish or salt water equally.  Ditto wet/dry filters, refugia, plenums, etc.

We do not very often use "protein skimmers", really foam fractionators, in freshwater because there is a substantial difference in the surface tension of the two liquids.  In salt water there is not much difficulty in producing the fine bubbles needed for foam fractionation to be effective and quite efficient.  This does not occur with fresh water, or only does with extremely high dissolved organics in the water.  Some heavily stocked Koi or goldfish pons do use foam fractionation or forced air drip towers to skim off the proteins, but that is only useful in such over-stocked situations
Also, generally in freshwater it is cheaper and easier to do partial water changes frequently and at high percentages of tank volumes rather than to use higher technology filtration techniques, which is the opposite of the situation in salt water.

There are no problems with your English.  You are doing quite well on that.

Title: Re: Why don't we use Protein Skimmer in freshwater tank?
Post by: Kim on April 13, 2008, 11:15:02 AM
Yep, you could if you wanted to.

I purchased a cheap filter from Dr. Fosters & Smith that has a built in protein skimmer, just out of curiosity. It does a nice job of removing the oily protein build up on the surface in a tank that I have problems with, worked well except that the plants keep getting in the way and tangling with the equipment. Sort of silly because it's those same plants that are allowing the surface to get oily because they interfere with the filter flow around the tank.  :)   I suppose I could move the filter to the other side or trim the plants but I like to make things difficult for myself.  :lol:

I have no problems with your english. :)

Title: Re: Why don't we use Protein Skimmer in freshwater tank?
Post by: h4nd on April 14, 2008, 07:25:46 AM
woww!! Thank you RTR...Grumpy Ole Fogie & Kim.
I am satisfied with your answer. Thank you for the enlightenment.

I will use my empty tank as a SUMP. Hm... have to find my overflow box first though ;)
My 40G tank will have capacity of 70G with the additional 30G SUMP.

And since I have unused Protein Skimmer, I think I will use it too.
A little bit overkill maybe? ... I'll see what the result first..


Title: Re: Why don't we use Protein Skimmer in freshwater tank?
Post by: Orever on January 07, 2016, 06:15:58 AM
I'm trying to figure out if I need a protein skimmer for my fresh water tank. I've been reading around and some people say you don't need on because you can do the same thing as a skimmer by just changing the water yet I've seen some people swear by them. As a newbie is a protein skimmer really necessary for a fresh water tank?

Title: Re: Why don't we use Protein Skimmer in freshwater tank?
Post by: rasaqua on January 07, 2016, 08:44:55 AM
If I was Robin in a Batman scene, I would have to say, 'Holy hydrophilic, holy hydrophobic Batman'. Batman would probably reply with, 'Holy polar molecules'. Protein skimming is basically a method of chemical filtration . While mechanical filtration removes and traps undissolved particles within a media, chemical filtration removes dissolved particles molecule by molecule. In a protein skimmer, this action occurs at the air-water interface of the surface of the bubbles that are created in the skimmer and basically a surface effect. The chemical properties of marine water allow this to happen more affectively than in freshwater. Large foam fractionators can be used in some outdoor freshwater ponds, simply by the amount of extra pollutants than can inhabit or enter the water that has little chance of occurring in an indoor aquarium.

Bottom line is that sea water has a greater affinity to produce the bubbles needed for the chemical attachment than fresh water. This of coarse is a very capsulized explanation.

Title: Re: Why don't we use Protein Skimmer in freshwater tank?
Post by: GB on January 09, 2016, 06:33:53 PM

Try out your protein skimmers certainly, but I doubt that it will do anything much in fresh water. I tried this when I first got a salt water tank. I had filled it with fresh water to rinse it out and tried the built-in pump and protein skimmer. The pump worked, but protein skimmer did not; I was relived when I put in salt water and it worked OK.

Good luck!


Title: Re: Why don't we use Protein Skimmer in freshwater tank?
Post by: BradenO on March 22, 2017, 07:33:56 PM
HI I'm new here but I wanted to add to the discussion, feel free to correct me about anything I say i am still in the infancy of aquarium keeping.

I have a 60 gallon fresh tank that I have planned to convert to salt. During that time a friend gave me a very large protein skimmer.

This is my learners tank, it has a overflow box that leads to a 40 gallon barrel and then into a 20 gallon sump. In the 40 gallon barrel I put the
Protein skimmer and as predictable the skimmer did nothing but move a water inside of itself. Understand that my tank is currently fish free and
the water is receiving ridiculous levels of filtration. It is equipped with a FX4 canister filter next to the sump and a large fluidized sandbed reactor.

I did however come to a strange discovery, by adding an adjustable air pump to the snorkel part of the skimmer I immediately got the skimmer to foam in a similar fashion to
a salt tank. My best friend owns a salt water tank service company and he thought I was crazy but was impressed with the discover as well.

I Imagine with more of a Bio load it would be an effect means of filtration especially if you plan on overstocking our tank. I imagine that the real reason it is not done is the cost of this kind of filtration which is not
really required in a fresh tank.

Title: Re: Why don't we use Protein Skimmer in freshwater tank?
Post by: russ on March 23, 2017, 07:23:44 AM
Without changing the subject too much, I just have to ask, what is the purpose of the 40 gal barrel? I'm trying to visualize a separate 20 gal sump, a 40 gal barrel and a fluidized sand filter all combined in the 'filtration loop' of your set up.

Title: Re: Why don't we use Protein Skimmer in freshwater tank?
Post by: BradenO on March 23, 2017, 05:42:42 PM
To increase the total water volume supplied to the display tank, complete overkill but it was an extremely cheap upgrade and the tank is in my office so it doesn't have to be terribly pretty.

Barrel is deceiving its just and additional sump I made out of a Brute trashcan before finding my wet dry sump but if you have it mine as well.

Title: Re: Why don't we use Protein Skimmer in freshwater tank?
Post by: moonbunny on March 31, 2017, 12:56:50 PM
Just to echo Kim, a freshwater protein skimmer is inexpensive and does a nice job of removing oils, dissolved proteins, polishing the water and, as such, increasing your surface O2 exchange just a bit.  It won't reduce the need for water changes (fish always seem silly-happy in newly changed water with an O2 boost), but, along with a quality filter, it will keep your water as clean as possible a little longer.

Btw...I love your dolphin!

Title: Re: Why don't we use Protein Skimmer in freshwater tank?
Post by: TwoTankAmin on April 02, 2017, 12:23:24 PM
I cannot see any reason to use a protein skimmer in a fw aquariums. That opinion was formed before I learned of the differences between sw and fw in terms of bubble formation. One place to look for interesting solutions to fw aquarium issues is the aquaculture industry.

In fact in many of my tanks I have taken another step and stopped using mechanical filtration such as floss. I am now using massive foam filters which have established the microorganisms which break down and consume a lot of the organic wastes and convert them to into plant and bacteria food in the form of ammonia. I have some pretty clean water as a result. This has also reduced weekly maintenance on such tanks by 1/3 to 1/2.

Nitrogen is a fundamental component of amino acids, which are the molecular building blocks of protein.
What is organic nitrogen?
Nitrogen is a naturally occurring element that is essential for growth and reproduction in both plants and animals. It is found in amino acids that make up proteins, in nucleic acids, that comprise the hereditary material and life's blueprint for all cells, and in many other organic and inorganic compounds.
from ( and (

For those nerds out there, ( and (
Those links are to a commercial site. I use some of their products and I know Dr. Stephan Tanner who is the owner. I am not trying to plug any of the products. however, both the articles linked are excellent reference pieces relative to fw filtration in general.

Going full circle to come back to sumps, I am about to set up a 45 gal. sump under a 125 gal. fw tank. This sump will only hold about 30 gals of water (the excess capacity will act as an emergency overflow space should the return pump go off. (It also made the foam size smaller which saved a lot of money.) The filtration is set to be 5 foam sheets, 3 inches thick and with different PPIs. They will be spaced 1 inch apart. The flow rate will be between 400 and 500 gph (a turnover rate between 2.6-3.3x/hour). I am not worried about anything on the surface or mechanical filtration.