Glass top question

[stainless_wm]

While reading a thread about leaving for vacation and the amount of evaporation I was going to suggest a glass top for the tank, which would reduce the amount of evaporation.
I just (in the last few days) had a piece of glass cut, for this very problem. and it will keep my light and tank stand clean. The piece of glass fits very snug and almost covers the entire top of the tank. the tank measures 36"X12.5". This piece of glass is just wide enough to only allow my HOB filters to fit in. It leaves about a 2" gap on the top of my tank.
The water level dosnt touch the glass top, but its close.
I was almost ready to suggest this to the other fella when I remembered something a friend told me.
It was something about surface area of a tank, and gas exchange of the air/water....

My question is,,, would this type of glass top in some way hinder the quality of the tank?


TIA

Wade

[dskidmore]

If you have a HOB filter, most of your gas exchange is occuring where the water is falling out of the filter into the aquarium. That gap in the back should be sufficient.

I have been using glass tops for about a year now. One system ran on a HOB filter, the other had an air stone. No problems!

I have recently cut down my glass top however, as I built a DIY light hood, and I'm concerned about heat buildup in my hood if it's resting directly on the glass. (I may have to get inventive and wire in a fan before summer, the fixture I used didn't accomodate top ventilation.)