Glass top or not?

[Rector15]

Will be setting up a 4 bulb t5 light fixture on my 75 gallon tank and wanted to find out the benefit of not having the glass top on the tank (other than electrical safety of course!)

 

[Mark Bianco]

Gas exchange is big thing, But if you have an open sump it not a problem. Second all glass tops will filter some of the light. You can lessen that by getting glass tops made out of Saffire glass. Glass tops will hold in the heat. Pluses to glass tops in the whinter they will help hold in the heat. Less evaporation. Keeps fish from jumping out...

Hope that helps
Mark

 

[a.browning]

Glass tops are generally frowned upon on marine aquaria. They prohibit gas exchange, block out light, and collect salt creep. If you're worried about jumping fish, you can make a screen top to keep the fish in. This can be an opinionated topic, but generally reefkeepers do not run glass tops.

 

[sail33]

Bow fronts are harder to cover. Mine came used without a top. The Coralife T5 also had no plastic cover. I had to buy an entire roll of 4 foot by 8 foot sheet of acrylic for the small strip to cover the light. Once that was done, I cut a piece to cover the rectangular area of the tank.

When that tank cover sheet broke, I felt like there was an improvement in the tanks gas exchange and haven't lost any fish. Access to the tank is also much improved without the top. I am considering putting egg crate over the top but am enjoying the full access to the tank too much and still haven't lost fish.

I say go without a top but with these conditions:
Light must be sealed as well as can be.
Light must be raised at least 4 inches above the water level to prevent creep.

I'm going to start another thread about the problems with the light and what might be a bad ballast.