<a href=showthread.php?s=&postid=11076240#post11076240 target=_blank>Originally posted</a> by seapug
Assuming you are talking about an ultrasonic fogger, please don't run it in the tank. These devices will drive your fish insane, if not kill them. To understand the power of these devices, put it in a bowl of tapwater, turn it on and stick your finger in the emitter where the fog comes from. It will hurt, bad. I find it hard to believe an aquarium supplies retailer would consider doing such a thing.
Not to mention it probably won't work in saltwater. If you want the "effect" put it in a bowl of RO water on top of the tank. The fog itself won't hurt anything.