Clown Loach

Question
My clown loach has recently stopped eating, has become thinnner until now he just has a tummy sticking out and absolutely no body fat. Ive had him for over two months and he has been a great lively fish. He developed ich but was cured and has been seemingly fine for a month except he hasnt been eating. Snails have disappeared and he will eat maybe one bloodworm or one brineshrimp per feeding time. He has been floating on his side like he's dying and doesnt even swim away from the net. Its not like hes just sleeping (ive seen him do that) and last time i caught him (to quarantine for ich) he was impossible to catch! What can i do!?
My tank has been set up since November, its 25 gallons, a community tank with peaceful fish, 15 fish, aquaclear 50 filter, ammonia and nitrite are 0, PH around 7.1-7.2, change water every sunday (it gets very dirty!) and the water is about a centimeter from the top i believe

Answer
Hi Julia;

Poor little guy. It may be internal parasites. See what the fish store has for it. I really can't say it's going to work though. The treatment may actually be too strong and be too much for him. You seem to be doing everything right with weekly water changes and feeding. It just happens sometimes and there isn't much we can do. I wish I could be more helpful...

At Your Service;
Chris Robbins