Fish Dying

[Alex&Kev]

Hi,

We've had our tank for quite a while (about 18 months) but have recently been having some problems. A few fish have died recently and we now have 3 who look quite ill. We would be very grateful for any help or advice. I've put all the detials below.

Thanks.


Tank size:60 litres
pH:7
ammonia:
nitrite:1
nitrate:40
kH:120
gH:170
tank temp:26

Fish Symptoms (include full description including lesion, color, location, fish behavior):
One of the neon tetras is misshapen. His back has fallen into a S shape (similar to a humans). He seems to be fine otherwise, he is not discoloured and is swimming around with the other tetras.
The mollie has become a little reclusive and is staying around the bottom of the tank as is the plattie.
We have had a few fish die recently: a mollie and a couple of platties.

Volume and Frequency of water changes:
15% every other week

Chemical Additives or Media in your tank:
Melafix and Water softener

Tank inhabitants:
6 catfish (2 adult, 4 babies), 1 Plattie, 1 Mollie, 4 neon tetras, 1 silver tip tetra, 2 black widow tetras.

Recent additions to your tank (living or decoration):
We removed the stones in the bottom of the tank as we thought it might be the snails causing the fish to die (their numbers have now decreased drastically). We also replaced the plants and got a big piece of bogwood from the pet shop. So I don't know if these new additions might be making the probelm worse. We also recently discovered the 4 baby catfish.

 

[fluttermoth]

Hi there; soryy to hear about your problems.

I'm guessing as you don't have a reading for ammonia that you're using paper test strips; is that right? It would be better if you could get some tests from using a better, liquid or tablet based test kit if you can.

There's obviously something going wrong; you sohuldn't be getting a reading for nitrite in an established tank. You need to do some large water changes with warm, dechloinated water to get that down for starters. Nitrite is highly poisonous to fish.

What kind of filter do you have and how do you maintain it? As you should have plenty of bacteria growing in there after 18 months to deal with the ammonia produced by your fish (fish roduce ammonia which the bacteris convert first to nitrite and then to nitrate which you reduce through water changes)

You probably need to do more water changes anyway; 15% every other week is not nearly enough; all my tanks get 50% weekly.

What is the water softener your using? Most people would not recommend using anything like that; plain tap water is usually best.

 

[Alex&Kev]

Thanks.
we we're using paper stips for the water but will take a sample to the petshop and get it tested properly.
The filter is inbuilt with different levels of sponges, we've just changes some of the filters tonight (but kept the older ones in the tank too for the bacteria).
The softener is called tetra aqua safe, which also declorinates the water.
I think we'll switch to one that just declorinates the water.

Thanks for your advice. x

 

[Mikaila31]

You really need a liquid test kit of your own.

 

[fluttermoth]

Thanks.
we we're using paper stips for the water but will take a sample to the petshop and get it tested properly.
The filter is inbuilt with different levels of sponges, we've just changes some of the filters tonight (but kept the older ones in the tank too for the bacteria).
The softener is called tetra aqua safe, which also declorinates the water.
I think we'll switch to one that just declorinates the water.

Thanks for your advice. x

Doesn't sound like you're doing too much wrong..except you don't ever need to change any filter sponges; that's honestly just a ploy by the filter manufacturers to get more money from you; I've got sponges that are 15/20 years old!

Keep up the water changes (they won't stress your fish; you can do 50% easily and you can do more than one a day) and invest in a good test kit (most of use here like and use the API one) so you can moniter your water yourself.

Get back to us if things don't improve