I believe my Oranda is sick and am wondering how to treat. I noticed him sitting on the bottom of the tank a couple weeks ago, but it was early in the morning and I thought he was sleeping. As of yesterday, he has begun spending most of his time bottom sitting. I don’t know how to tell if he is “gasping” for air. I definitely see his open and close, but his breathing doesn’t appear rapid. He swims when I come by the tank and feed. Occasionally he goes to the top to gulp air (he’s always done this). His swimming appears normal. He has had semi-recurring cotton on his head the past couple weeks as well, but I do not see any now. The other fish in the tank act fine.
Aquarium: 65 gallons, 4 goldfish and 1 pleco
Age of tank: 6-7 months
Filtration: penguin 350 power filter
Temp: 70 F
Food: topfin goldfish flakes 1x per day
I usually do 50-75% changes every other week, but it has been about 3 weeks since the last water change before I did a 50% change yesterday. I will do another tomorrow. In the meantime, I used Prime to detoxify the ammonia and nitrate. Nitrate levels are always a bit higher than I would like.