So I have 3 bangaii's and the smallest one is very skinny and missing most of his fin .he is swimming slow and with its head up I put him in the sump . I have a pick if I would help .also I returned a watchman goby today because it was very territorial and nipped at anything that got in " his 1/4 of the tank I think that's what happened but I'm not sure the other 2 are just fine and all the other fish are fine also .oh and I've had them about 2 1/2 months water was great on Sunday ill test then post in a few and ill post a pic also thanks in advance