I Had a bad outbreak of ich and killed 3 out of 5 fish I had in my 90gal main tank. I put the 2 others in a 10gal quarantine tank and treated with coppersafe and all the spots where gone and fished looked healthier. Well I used the water from the main tank to fill the quarantine tank and used a HOB filter with a bubbler.

Since the beginning my nitrite and ammonia levels have been off the charts, So I did 20% water changed every day and just cant get the levels under control and water is cloudy, been 22 days and eventually one of the fish died and now left with one fish.

2 days ago, I had a spare fluval 405 filter laying around with bio media and placed that on the tank with some biological bacteria. And seems to be bringing the levels down a little bit but not enough to stop dangering the only fish left. The fish doesnt look very healthy right now and im sure its from the bad water levels.

My question is do you think it is safe to put the fish back in the main tank to give it a fighting chance of surviving?
The main tanks levels are all perfect and I have been running the temp at 86 degrees for 24 days now to get rid of the ich.

At that temperature for that amount of time, assuming no hosts in the DT, you should be safe to put it back in there so long as it doesn't have ich.

__________________

I think everything is going to be pretty safe. As long long the temperature stays at 86 degrees, im sure it will be all good.

__________________
Visit my blog below and learn about the mistakes you must avoid when making your first aquarium.

http://www.how-to-take-care-of-an-aquarium.blogspot.com