Tank Cover...

I think you need to consider your sump set up as well – I use glass lid’s, but I also have a 55 gallon sump and 45 gallon refugium in my basement which helps with cooling and gas exchange. If you are not set up to allow for gas exchange than I think you need to consider that as well as heating issues. With that in mind I agree with M2434, a pond netting build would work very well.

 

I use the window screen frame with a cut up pair of "fishnet" stockings I borrowed from my wife. It has kept my wrasse in the tank the few times he has jumped. I use the glass pieces from the original cover for the front of my tank as it is a bowfront. I haven't noticed any ill effects from this, although I am running T5s.

 

That works, I also used that and went to try those squishy shower soap thingies (shows how much of a guy I am). Buy a new one and take it apart. It's durable and let's a ton of light pass through.