what is this on top of my water??
its in both tanks 55 and 40. all water test show that water if fine but what is this will it hurt my fish?
both are new tanks that were just set up? i have never had this happen before tho.
I bet it's oils from your fish food. That happens on every tank that doesn't have an over flow to skim the surface water. I added a glass-holes.com overflow to my 360 just for this reason.
It wont hurt your fish, it could restrict the oxygen getting into your water but if your fish are acting fine and not at the surface gulping air then your tanks O2 levels are fine.