Glass cover and light transmission

[stunner]

I'm doing some research into SW coral tanks, and I read somewhere that the use of a glass cover over your aquarium can block out important parts of the spectrum in actinic lighting. Is this true? I haven't really come across this anywhere else, so I'm a little suspicious. I'm HOPING to start a 10gallon with zoas and mushrooms. But we'll see....lots of research yet to be done.

thanks

[cocoa_pleco]

ive heard that too, and it may be true. however, all my reefs are open top. as long as you dont have water splashing alot go with open top tanks

[stunner]

I'd rather have covered tanks. In the winter we keep our house temp. somewhat low, and when I had my open top 15 gallon in my room it lost water so fast. So I would prefer a glass cover...but if it does block out parts of the spectrum, I guess I could go open top.

[unleashed]

it is true. I have seen the data somewhere. With the same data, I also found that with an open top, and lots of surface water movement, the light intensity can be up to 25% greater

[jttt3]

I don't have a cover on my tank, and I am loosing about 1/2 a gallon+ a day. It's frustrating keeping the salinity level at a constant rate, which is affecting the corals worse than lossing a bit of light spectrum.

Most tank lights come with glass or plastic covers anyways. They also help keep splatter off your lights and light covers and keep fish inside your tank (jumpers). I know I rather remove and clean a piece of glass than take apart or remove a delicate plastic cover from my light and try to scrape the salt off without damaging the cover.

I say that the benifits of having a cover outweight the downsides.

Though on the otherhand if you have metal halide (or 2) without a cover hanging 18" off the surface of the water and are ok with topping off your tank at the higher rate of evaporation, I'd say do without the glass cover.

It's all about reasonable maintenace and what/how you are willing to compensate.

[CAF]

Most of my tanks be they FW or SW are open top. I do have a few with glass hoods, but they are the rarity not the norm.

[Lady Hobbs]

I have problems with my glass covers remaining clear. I have hard water and constantly having to clean the glass. Bubbles popping at the top splash on the glass leaving those hard calcium spots and deminishing the light.

I plan to get the legs for my lights and just removing the glass covers. Adding more water a couple times a week would be easier than scrubbing the lime scale off that glass.

[CAF]

Adding more water a couple times a week would be easier than scrubbing the lime scale off that glass.

Thats why I have been switching over.... LOL Razor blades were my best friend for a while.

[Lady Hobbs]

Straight vinegar works great. Pour it on and let it set for 5 minutes and it eats thru that crust. I buy A LOT of vinegar. LOL

I also notice the lense cover on the coralifes can get nasty if you try to use them without a glass cover or legs. That can scratch easily and also diminish the lights so the legs are a must, IMO.

[cocoa_pleco]

for some reason my 55g doesnt lose much water to evaporation. since its been setup (a month about), ive lost 3".

[stunner]

I agree with Lady Hobbs about the annoyance of scraping off the deposits from bubbles popping against the glass. We have really hard water here too. But I also found that in the winter, since I can easily lose 2'' of water from my 15gallon in three days, there was an ugly layer of hard deposit around the tank. Hmm.....I don't know what to do, I'd really like to keep a glass cover on. I guess I'll put a glass cover on for a while, and see how everything does. Thanks for the input!