Mermaid Goldy

I apologize for the sucha long post ....
I have had 2 Pearl Gouramis for about 1 year already. Within this year... they were moved from a 40 gallon to a 90 gallon. In this 90 gallon there are 4 Rainbow fish (1 (formerly 2)red and 3 of those blue/yellow ones), 2 Angels, 1 Discus, 1 plecostemus, and 1 goldfish. The goldfish(about 8 yrs old) and the plecostemus (about 5 yrs old) are the oldest fish. We have live plants, driftwood, and a JEBO external filter; also, everyone gets along for the most part.

So now that you have the rundown of the tank's setup here is the problem.... 1 of our 2 Pearls has never eaten much and looks like a dwarf versus the other Pearl. It doesn't seem like he/she has grown much since we got them 1 yr ago. A couple of weeks ago we noticed the small gourami looked bloated. We noticed that she had fin rot as well (the goldfish also began to get tattered fins). The water was tested and the ammonia was only slightly above normal. A water change was implemented and fin rot med Maracin 2 was put into the tank. Followed the instructions and finished the treatment. The goldfish began to recover but then the Pearl and a now dead Red Rainbow as well as the 3 blue/yellow Rainbows became bloated. We treated the whole tank with Tetracycline per a local shop owner's advice. The 3 blue/yellow Rainbows recovered and, at the time, the Pearl Gourami seemed to recover also...1 Red Rainbow died though. 1 week later... water quality is back to normal and some plants were re-placed, but the it was then that the Pearl Gourami began to sink to the bottom on it's side and began to float with it's head touching the gravel. I immediately put it into a 10 gallon tank for quarantine (this was 2 days ago). This gourami is now swimming around the 10 gallon almost normally(normal body movement but front of body cocked a little lower than rear of body) and it's not eating.

I know this is a lot of info and there may be several questions I may still need to answer to receive prioper help, so feel free to ask. Does anyone have any idea what might be wrong with this gourami and what might have happened in my tank? I want to help this Pearl make it. Any help would be greatly appreciated.

Shawnie

welcome to fishlore!! im not sure what you mean by "ammonia is above normal"? no ammonia is normal and should be at 0 as well as your nitrites...was the 90 gal fully cycled before you added fish?

if so, did you add all the fish at once and maybe overload the good bacteria?
as far as the goldie, hes not a tropical fish and does best in cooler temps..so maybe put him in a cooler tank where he was before?

if you arent cycled, daily water changes with some prime to neutralize any ammonia or nitrites for 24 hours, and some maybe some vita chem to help mr gourami feel better, will help alot..goodluck!