Heya. I'm new to this site but not to fish. I've currently got 3 tanks running. A 180 litre with angels, clown loaches, a black ghost knife fish, a BNP and a discus. Heavily filtered and lots of water changes. A 54 litre with 2 amazon puffers and 3 cory's, and a tiny 20 litre with neons. I've...