I have a two year old oscar who has not eaten for three weeks. He is unable to get to food because his stomach/bladder has bloated so much that it keeps him floating at the top of the tank on his side. I have tried epsom salts (in a hospital tank), tested the water (high nitrate, water changes every two days for two weeks - no change) have tried to feed him peas but he can't get to them, and even when I dangle one at the end of a line he shows no interest. He tries really hard to fight his way down into the tank but just isn't able. I've called vets, aquariums etc. but noone seems to know what to do. I don't want to keep him alive if he's starving or in pain.

Could someone please advise as to how long is too long to let him go without food. I love him so much.

Thanks guys.

Fish can go without food for a few weeks. Certainly three weeks. However, I am afraid this situation doesn't sound very good. I am not a trained vet so I can't diagnose your problem. However, a friend of mine had a very similar dilemma to yours. Her Oscar seems very much of balance and sat funny in the tank. I think it probably was down to an internal bacteria infection, or a problem with the swim bladder, or both. She euthanised her fish because that was the best thing to do. You probably don't want to hear this but if this situation carries on much longer, I think you are going to have to think about euthanasia. It would be the best thing for the fish. It seems that you have tried everything and asked professional advice and haven't got anywhere. We are here for any support and advice that you need.