Will a glass cover effect my lighting?

[Fatman]

I plan to put a glass cover on my tank due to excessive evaporation, will this effect my lighting for a reed/invertebrate tank?

[Reptoreef]

It will definitely effect lighting as well as limiting gas exchange. IMO, if you have the ability, set up your system for automatic top-off for the evaporation.

[carpenterwrasse]

how do you design an automatic top off system....

[Fatman]

Thanks for the info guys! Got it will try to leave the top open.

[davejnz]

Glass covers are the worst thing you could put on the top of your tank.As Repto said,it
affects gas exchange,this exchange happens for the most part at the surface.This affects O2/CO2/PH levels in your tank.The glass will also block some of the light/UV from your fixture/canopy.
C-wrasse,auto top off can be as simple or as complicated as you want to make it.I prefer a simple gravity fed system that goes to a float-valve in your sump.I use a 5gal bucket for a top-off water reservoir.Take a threaded RO fitting(female fitting to accept the tubing).I install this fitting about 1" from the bottom of the bucket(this allows the kalk impurities to settle so they dont enter the tank).I then take a short piece of RO tubing and push it into the fitting.I attach a RO shut-off valve that has female ends on both sides to the short piece of tubing.From the other end of the valve,attach some tubing that will go to the float-valve in the sump.

[dakar]

Cwrasse here's my simplistic design.... working very well.

http://www.captivereefing.com/viewtopic.php?t=1243&highlight=dato