So, I had two 1/4 inch plates of acrylic cut to act as covers for my display tank. I did this for the following reasons.
1.) To prevent fish from jumping out.
2.) To reduce the noise from the overflow.
3.) To prevent evaporation.
4.) My lighting (Nova Extreme Pro) instuctions emphatically stated not to use them on an open tank.
So, are there any drawbacks to having my tank covered? The only one I could think of was gas exchange, as there is only about a half inch between the plates and the water column. I figured that with all the flow through my sump/refugium and my skimmer mixing things up there would be plenty of gas exchange.
I ask because when I was originally setting everything up my LFS
recommended not having one.