using glass covers

i'm curious what the ratio of "covered" vs. "uncovered" tanks are...
i added an eighth inch thick glass cover today to my tank basically because i can't keep up with evaporation and salt spray is driving me nuts,
it must be blocking some light,but how much? enough to matter? it gives me a little concern as to gas exchange also.

 

I would try an automatic top off instead if keeping up with evap is your problem. Covered tops compromise gas exchange and can make your aquarium temperature go higher than it would normally.

Unless you are afraid a fish is going to jump out I wouldn't cover it. (And if it's a fish you are worried about later on, then try a screen, not glass covers.)

 

I also had to cover mine as well as all the evaporation leaves a film all over the furniture that is in it's room. On top i have about 90% of the tank covered by plexy glass and I keep the 40gal fuge open with the cabinet doors open as well for gas exchange. I had to add a chiller to keep the temp where I want it. I lowered the lights about 2 inches and have seen no changes with the fish or coral. Good = less evaporation, Bad = freaking expensive.

 

I don't cover my tank and never would. Oxygen exchange occurs at the water's surface so even if you expose your sump and refugium, you're not really solving that problem. As for blocking the light, if you keep the glass clean, it shouldn't be an issue.

 

I'm using glass covers, and have about 95% of the top of the tank covered. Gas can still be exchanged from water to air using a powerhead to agitate the water surface. Lids get opened at least a few times a day to feed, replace seaweed on the clip, turn over a snail that's on its back, etc.. I know that an open top is better, and we'll see what the temps hit this summer using those lids. I'm using PC, not MH so hopefully not much of a problem here. With glass lids, I'd think you could prop them open an inch or so to let more air in-out if you needed to.

 

I am 50% covered right now, just to seat the Light fixture that is too small for the tank. Once I get my new light, the cover will come off. Currently the splashing covers the glass with salt anyway so that cuts down the light power. I am now using small pieces of thin plastic placed where I have splashing to keep the mess to a minimum, seemes to work well. For example, over where I have my air stones, I placed a piece of plastic, no more mess.

Pro -
Keeps splashes away
Keeps jumping fish in, (Good alternate for this is egg crate)
Can be used as a shelf

Con -
Dirty glasss cuts down on light power
Glass cuts down on air surface gas exchange
I think helps to raise the water temp to have a tight glass top


My .03

\Cheers

 

mine coveres up about 90% the reason being my cats love to watch the fish and sometimes they try to jump on top the tank (they never actually have) but knowing my luck if i were to get a lid that didnt cover up it be the one time they did make it up there.
the very back has a opening and when im home i leave one of the lids open. (im home alot) :-[
not to mention the salt does something to the walls. makes the paint chip. annoying

 

About 3/4's open. But thinking about removing the glass altogether...

 

Gas Exchange should give you great concern.

Salt creep will also quickly fog glass and you will be constantly cleaning it...will drastically reduce light effectiveness.

Top does need to be as open as possible...:-/

 

I personally have a glass top but that is mainly due to two little boys 3 and 1 that like to throw food everywhere I would rather deal with constant glass cleaning and gas exchange than spikes in perameters due to unwanted food falling behind rockwork. But that is just my little issue.
I think it comes down to what you can do. If I could I would leave it open.