Guppy breathing rapidly

[FinNipper]

Hi everyone!

A little over two weeks ago, my guppy started to scratch his gills against the gravel and breath heavily. After I moved him to the hospital tank, I tested the main tank for ammonia and nitrites(first time ever..I've learned since thanks to you guys). Ammonia was .5 and nitrites were around 2-3ppm(both almost down to 0 now). So he may have gotten ammonia and or nitrite poisoning or something else all together. He's been in the hospital tank for 12 days..

Hospital Tank(2 gal explorer)

July 22 - Added Salt/Quick Cure
July 23 - Added Quick Cure
July 24 - Added Quick Cure
July 25 - Added Quick Cure
July 26 - Added Quick Cure/25% water change
July 27 - Added Quick Cure/Tetracycline
July 28 - Added Tetracycline
July 29 - 100% water change - Added 3ts of salt/Tetracycline
July 30 - 20% water change - Added 2ts of salt/Tetracycline
July 31 - 20% water change - Added Tetracycline
August 1 - 20% water change - Added Tetracycline
August 2 - 20% water change - Added Tetracycline
August 3 - Cleaned out

He's very active, eats normally, and hasn't been scratching himself..lol..for a while now..but he's still breathing heavily with his mouth opening and closing non stop. I put him in the main tank today because I didn't know what else I can do for him. He was SO happy to see his friends but the breathing hasn't changed. Could he have permanent damage to his gills? TIA

[azn dreamer]

Is the water well oxygenated?

[FinNipper]

Yes it is, I'm using a bio-wheel and I have a bubble curtain in there.

[tkos]

It might just be that he has permanent damage to the gills. What type of pleco do you have in that 20 gallon tank?

[FinNipper]

A comon pleco, he's about 2 inches long minus the tail.

[tkos]

I would take that pleco back to the store asap and trade him for a dwarf pleco. Commons will grow to be 24 inches long and produce horrid amounts of waste. You need at least a tank that is 4 feet long to handle him. A dwarf like a bristlenose will only grow to 4-5 inches and will work fine in that tank. The longer you leave the common pleco in your tank the more he will be stunted as an adult. But that will still not stop him from growing too big for your tank.