All fish are ok with the exception of a amazon bumblebee catfish. It hides sometimes so hopefully it's ok. Did test a couple of the aquariums and parameters were surprisingly good. I was thinking that by me not filling my aquariums all the way up may have helped. I say this because non of the fish were at the surface. Also non of the aquariums are overstocked. I did pour water over the media for a couple of aquariums. Only have 2 battery operated air pumps going to order 2 more. The batteries lasted the 2 days.