# glass top vs open



## joshvito (Apr 6, 2009)

In general, i use glass tops for all my aquariums.
I believe them to battle evaporation, and help keep in heat in the winter.
(and keep the fish in the tank too)

I am wondering what your thoughts are on if they affect the quality of light coming off my 4x T5HO bulbs on my standard 75G tank.
I wipe the glass at least once a week, when I do a change, but there is condensation on the underside of lids every day.

Any and all thoughts welcome.


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## freshyleif (Jan 9, 2008)

I took my glass tops off and built my own lid following somebody's DIY example on here. I think that as long as you are wiping them every week they should not make that big of a difference but the glass does reduce some of the light getting to the tank. The issue of evaporation is something I find easier to deal with. I like to top off more than cleaning the glass.


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## Franzi (Dec 7, 2009)

This topic has been beaten to death. A search will give you all the opinions you'll ever need. It's all opinion/preference.


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## WhiteDevil (May 7, 2009)

the more you top off the more you are cleaning glass pending water source.

I have open and closed top tanks, my open top tanks grow plants taller not fuller, not lusher. I keep a layer of water lettuce on top to contain the fish. My closed top tanks evaporate at 80% less rate then my open ones do during the dead of winter here in chicago( evaporation can be watched) and the plants grow fuller and thicker and not as tall.

What do you prefer? what are your reasonings behind the question? 

also if you are up against drywall(gypsum not greenboard) with an open top in a heavy evaporative demographic you can cause more harm then good to everyone in the house.


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## joshvito (Apr 6, 2009)

@whitedevil, I was mainly concened that the top filters/reflects/refracts some of the light away from the tank. 

Has anyone set up a controlled experiment to test this?
I think it would be interesting.

@fRANZI, Thank you for the responses, I'll search some archived posts.


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## tom855 (Feb 5, 2006)

It may not be controlled but I can tell you that my 36" glass top was so white with buildup that I couldn't get it off. I cleaned it (or tried to) about every six months with Lime Away and a razor blade. It would get some stuff off but would never look good. I too was concerned I was blocking a lot of light from the hard water leftovers. Finally, after about 3 years of buildup, I got a brainstorm..... buy a new piece of glass. It cost me $11.50 at the local glass store to get rid of all that buildup and put in a new piece of glass. It definitely made me happy with the appearance, but there was no detectable difference to my eye, nor did the plants change their appearance, pearling, or anything like that. I'm sure that some amount of additional light was being let through the glass, but I'm not sure it was anything significant. It was nothing compared to the delta in light from replacing aging bulbs in my fixtures. Personally I like the idea of the cleaner glass, but I'm not sure how much it really changed.

Hope that helps!

Tom 

.


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