Save Fish from High Nitrites

Question
I have a 10 gal. tank that has been set up for two months. It was set up for two weeks before adding fish. I had a painted platy, a molly, a male guppy, a cory catfish and a dwarf neon blue gourami.  At the end of July, I had my water tested and all the chemistry came back normal. I went on vacation for one week.  Had a friend feed the fish.  When I got home, the platy and molly were dead, still in the tank. I took my water for testing the very next day; the nitrites were 5.0, and ammonia was 0. Probably over feeding by my friend and leaving the dead fish in.  For the past 10 days, I have been doing 20% water changes daily. Today, I lost the guppy. Finally, tonight the nitrite levels are reading .25. I realize it needs to be 0. Hopefully it will be with the next water change. On one side of my gourami, it looks like the "blue color" is flaking off. It is looking pink or pale in color.  The cory'e eyes are almost black and both are lethargic. I've read about brown blood and nitrite poisoning, so I'm sure that's what is wrong with them. My real question is, can they be saved?  Should I move them to other water?  I don't have a hospital tank.  I just have an old 2 gal. gold fish bowl.
My other questions are: How long should I wait after my water is healthy before adding a few more fish? Would it be dangerous to my current fish (if they survive), to bring in others?
Thanks for your help.

Answer
Hi Mary;

Keep making those partial water changes until the nitrites are at "zero" and stay there for at least a week. The surviving fish are healing from the burns caused by the elevated nitrites. The black areas and sloughing of skin and scales are the damaged tissue. I don't believe it would help them to move them out, it would just stress them more. The damage has been done already and the nitrites seem to be going down now. Make sure there is plenty of oxygen in the water (maybe add an air pump and airstone) and also add aquarium salt. The salt combats "brown blood", a symptom of nitrite poisoning. The salt allows more absorbtion of oxygen, re-altering the blood cells to a more normal state. There isn't much else you can do for the fish at this point.

Add a new fish or two once the fish you have are recovered. It could be two weeks or more, and they may not make it at all. Hopefully though, they will live through this and have some new friends to share their little home with soon. Go very slowly and add maybe one or two fish a week until the tank is at the desired maximum population. Your tank can handle a maximum of 10 inches of adult fish safely. Slowly raising the population like this will allow the bacteria balance to grow and compensate for the each new fish and toxins shouldn't go out of control.

Followups welcome

At Your Service;
Chris Robbins

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