Dieing fish

Question
Hey Chris,
I've asked you a couple of questions already and you've been really good with your responses. The problem I am having right now is that I am losing some fish, some fish I have had for a really long time. I've lost a bala shark about 7" long a large royal pleco and my smaller bala shark of about 4" is looking pretty ill. Also a few of my larger tetra's are breathing at the top like they are gasping for air. But all the other fish cory's, the other plecos catfish all seem to be doing fine. If you recall I had some really high nitrite levels a few weeks back now they have dropped down and they are about 0.1-0.3. The pet store suggested I do water changes of 30very other day until they have completely disappeared. Using a chemical called Prime its a nitrite/nitrate chlorine and chloramine remover. But before I started that I wanted to know what you thought. All my other current levels are good PH is about 7.5 a little high but not bad. My fluval 404 is currently set up with one layer of bio-max next level with a layer of carbon and bio-max next two levels with foam. So any advice you can give the sooner the better I really don't want to lose anymore fish thanks.

Tom

Answer
Hi Tom;

I'm glad I could help in the past, and I hope I can this time too...

The fish store gave pretty good advice, but only change 25% and do it every day until the nitrites are 'zero'. Prime is just fine to use. Also add aquarium salt to help the fish absorb more oxygen. Nitrite poisoning causes a change in the blood known as "brown blood syndrome". It keeps the blood from absorbing oxygen the way it should. The fish basically suffocate and it does seem to affect the more active types that require higher oxygen levels. Salt helps reverse this syndrome. Add an initial salt dose of one teaspoon per gallon for your entire tank. Every time you make a water change, add only enough salt to treat the newly added water. Once the crisis is over, stop adding salt and just do your regular weekly changes of 25% with a gravel vacumming.

The next task is to figure out why your tank keeps having nitrite problems. It's usually overfeeding. If you feed your bottom fish any extra foods, that's probably why. It is easy to overfeed those. Let me know if I can help you with that...

At Your Service;
Chris Robbins