Cover for tank/sump?

I am considering covering either my sump or my DT and had some questions. If I do this I will be using 1/8'' Lexan plexiglass which is UV sterilized. First of all I know one side has to be facing the lights but will that greatly reduce the light that gets through by covering it? If I cover the sump instead will it lower the growth of the algae in my fuge? Will covering it cause the temp. to go out of control? The main reason I want to cover some of this up is due to the amount of evaporation occurring. I am NOT trying to cover the entire system just one of the two tanks (DT or sump?).

Thanks for any input!

 

you really dont want to cover your tank unless you HAD to like if you had a bird or something. evaporation is something we all have to deal with. covering would reduce the gas exchange and could trap heat in the system.

 

I understand that, that is why I was thinking covering only one of the tanks wouldn't cause to much of a problem. Both tanks (sump/DT) are 48 x 18 and the DT is 24 deep the sump is 18 deep....? If I only cover one it would still allow the other to exchange/evap. but would cut the evap. in half? I have also seen tanks at my LFS that come w/ covers. One was a 1200 gal. and had a cover over the entire tank.

 

there are cons to covering - mentioned above.

your goal of reducing evaporation *may* be reached by this slightly, but absolutely not fully. I think this will only marginally make a difference and may be so negligible that you won't even be able to measure it. (unless it's air tight, it'll still go on evaporating)

with that in mind, I would think the cons out weight the minuscule potential benefit realization of your objective...

I wouldn't do it.

I would get an ATO and make the entire issue moot.

 

Thanks for the info! and just to clarify I am not trying to completely eliminate evap. because I understand it is good. Just trying to cut down some of the water surface area it can evap. from by covering some of it. I used to run my 30 gal. (now part of sump) with a cover and it obviously still evaporated but not nearly as fast as it would w/out a cover.