I have 1 red eye tetra that has been in my tank for about 3 months and tonight it is swimming sideways and failing to the bottom on it's side. I placed it in the breeder tank so it wouldn't be picked on by the other fish like it was. What should I do with him? The only difference in the tank is I added 7 neon tetras today.
Well the red eye tetra is from a group a 7 including him, and they all have gotten along fine with the other fish. I also placed a Giant Danio in the Friday. I had totally forgot about him. I didn't figure the neons had anything to do with it, unless he swallowed one by some chance. My water test came back
Look into swim bladder like bob said, but some water changes are in need with your nitrite reading. Do a series of small water changes over the next few days to get your nitrite down and i'd suggest 50% just now. with you having nitrite, there is a very high chance amonia is also present, or at least has been very recently.
A hospital tank would be a better optin than breeder unit if you can. I find the breeder units stressful, but if he's being picked on it could be the lesser of the 2 evils. Sorry, I'm not really sure on this one.
What test kits were you using? I recommend a liquid test kit over test strips any day. The strips are so inaccurate that IMHO you'd be as well not testing at all. I have used both Nutrafin and API master liquid test kits and found them both to be really good. They're not that expensive either since they last for AGES.
I re-read your post there. I've never had a fish with swim bladder to cmpare but with you saying it falls to the bottom it makes me suspect it's not swimbladder. Swimbladder usually means the fish has problems geting TO the bottom. When he falls to the bottom does he stay there for long?