Hey! Our comets spawned just over summer, and we set up a 75 litre tank, which currently holds about eight 1 inch fish. It's currently unfiltered, and I know it should be, but i'm worried introducing the filter will knock off all the fish, once the nitro cycle starts. 30% of the water does get changed every week. And it is full of plants So the short of it is: Is there a way that a filter can be put into the tank without killing all the fish? I really dont want to kill the little guys! Note: i dont really know any of the specs of the tank right now sorry. Thanks!