So Pog dies like 2 weeks ago at the age of 3 and there was an open spot in that tank, so I scrubbed everything and did the regular qt and a couple days ago I put in Jalapeno, who had been in a plastic tub, I did the temps right. The nitrate was pretty high in the tank so I had done a 50% change and there was alot of floating debris because I didn't want to do more that a 50%. He started being lethargic and swimming spurratically (like not moving and suddenly really fast everywhere and then not moving) and he got stuck on the filter even I have never seen a fish get stuck to that one. I decided to do another 25% change and go to bed and the next day when I got home from school he was fine. Was it stress or something? It was half a 20 gal he had. but I have 2 ten gallon filters in there.