Are my fish happy?

[papaloach]

A couple of my clown loaches i`ve noticed, there dorsal fin is down quite often lately, is that a sign of ill health? or is it me just worrying, i always keep track on water changes making sure all the craps gone and cleaning the fluval 204 extarnal filter, Plus i`ve replaced the carbon and the amonia remover recently!
Just hope there happy clowns

[Diana]

Usually an upright dorsal fin is best, and a low one suggests something is going on. Perhaps social, perhaps something else.