Hi everyone, registered here as I purchased a 90-litre tank second hand the other day and have a question I thought you may be able to help with.

Bought the tank, including fish on Wednesday, got it back to my flat and all set up, ran it for a couple days then went and purchased more fish on Friday. One of the fish I bought was an angel fish and he seems to be acting strangely.

When I turn the lights on, he disappears in a corner and doesn't emerge again until I turn them off. He won't feed or do anything until it's dark in the tank. Is this usual behavior for an angel?