Badman's Tropical Fish

All-Water Boards => General Discussions => Topic started by: Rushfreek on November 14, 2018, 10:26:42 AM

Title: Help please.. New tank, just added new fish and they die.
Post by: Rushfreek on November 14, 2018, 10:26:42 AM


54 litres 60cm x 30cm x 30cm
HOB filter 450lph and sponge filter (20 gal rated) small power head for surface agitation
Co2 via bell type reactor
Heavily Planted: Anubis, Hydro Poly, Hair Grass, Crypts and various others
Eco Complete substrate
Air stone & pump
Dragon rock (from an existing tank)
RODI water with Equilibrium and Prime
Fluval Cycle and AQ salt

I recently decided to change to a RODI set up because of bad tap water in my area of the UK. Thanks to Seachem's techs for the advice and formula for the Equilibrium for the batch sizes.

Mid tank cycle I swapped out the substrate having decided the original substrate (in the tank for 7 weeks) was sub standard. It was, I believe causing all the live plants to die and rot really quickly, and cause really bad sulfurous smells. I put in Eco Complete to a depth of 1 1\2" (front) to 3" at the rear of the tank. I realised that this would break the cycle of the tank, but thought it was worth it. I reused most of the live plants, filter media etc, and dosed with Cycle to get the good bacteria going again. I have also added media and rock from a well matured tank.

After waiting 5 weeks (plus the 7 weeks previous) I took the plunge and added 4 Silver Tip Tetra and 2 Cory's and 2 Neritite snails. Within hours of adding them to the tank 1 had died. I then saw a further 2 of the Silver Tips swimming very erratically, mostly into the flow of my surface agitation pump. Both snails still alive as I write this. Did a 20% water change.

Within hours they both had died, and the Cory's were dead by morning.

I tested everything with my api kit, and the results were as follows:

Ammonia 0 ppm
Nitrites less than .25 ppm
Nitrates 10 ppm
PH 6.83
Temp 79.1 f
GH 10 drops
Kh 10 drops
TDS 291

So, please could anyone give me so advice to where to go next. Do I add more fish? Do I try something different to Fluval Cycle? Give up on RODI Water? Or anything I have done wrong. This is the first new tank I have set up in many years, and have never had this issue before.

Sorry for the long message, but any advice/help will be gratefully received. Thanks.

Title: Re: Help please.. New tank, just added new fish and they die.
Post by: russ on November 20, 2018, 09:09:45 PM
Sorry for the late reply,

From the symptoms of the fish you mentioned, I suspect the fish are acting to a toxic compound in the water. Could be from tap water or somehow manifesting within your tank. Also recheck your water testing protocols to make sure your are testing correctly or reagents haven't expired. Don't add any more fish until your go through your water protocols again. also, has your biological filtr media been compromised in any way that you know of?

Title: Re: Help please.. New tank, just added new fish and they die.
Post by: ayushmhr on November 24, 2018, 01:12:17 AM
Hello, sorry for your loss,
my first question is, how many hours do you switch on your coz and lights?
i had same problem when i started a planted tank for the first time. i found out that, my co2 was running all day and night which turned the water toxic. are your plants healthy?
what lights do you use?
if you are resetting your tank again, try to cycle your tank for a month and then add a hardy fish first. like zebra diano, let them be there for a week or so, test your water parameter and then only, add your Tetra. did you acclimate your fish before adding to your tank?
Here is the link i found helpful: