Tops or No Tops?

[Aqua Man]

Well I have asked a few local friends here who also are reefers, and just cannot come to a conclusion. I want to know if it is better to leave your glass tops on when you are running metal halides and power compacs. I currently leave the glass tops on during the evening to reduce some evapouration. During the day when my lights are on I remove the tops, but she evapourates more quickly. I do this with all my reef tanks....

So is it better for the corals with the tops on or off when running the lights?

[kien]

How is your heat doing during the day with halides? That insane evaporation is your tank cooling down. Usually a good thing :-). I run topless and even have to use a fan blowing across my water surface to help cool my tank down. This evaps water even more so! Topless also helps harmful gasses to escape from the tank. Is the evaporation just annoying or is it causing issues? Do you have a automatic top off? If not, I recommend getting one to help your sanity :-)

There are quite a few threads in here on the subject.

[fishytime]

I like topless

[danny zubot]

I voted topless. I had a glass top crack once due to heat from my halides. While this is not the norm, in my case the lights may have been too close to the glass, and it eventually gave way. All of the other reasons listed above are very valid.

[no_bs]

I go topless on the main, tops on the sump and frag tanks. After putting tops on thoes tanks, evaporation was almost cut in half. Wish there was one more option.

[ponokareefer]

I have a top, but it fits overtop of my lights, and is a fabric with a lot of really small holes that I have stapled to my "open" canopy. It keeps fish in, but still provides air flow. Aquarium Illusions makes the "open" canopy, you just have to find the fabric to staple to it.

[Aqua Man]

I agree the temperature does not heat up as much during the period when my metal halides are on; if I remove the tops. I am ok with the excessive evaporation, just want to know your opinion, if the corals get better light with or with out the tops. I would assume the glass would filter out vital energy for the corals, but I have also heard the glass magnifies the light and can cause your corals to grow faster... personaly I do not use tops, just at night when the lights are off to hold in the heat and reduce some evaporation.

[zum14]

I voted topless even though im running a glass top now, the only reason im doing so is to minimize evap but more importantly to protect fish from jumping since i dont have a canopy yet. The next tank will have a full surround canopy and will be open top. I think the gas exchange is important and if you run a glass top keep your nose close when you first open it, it may surprise you how much accumulates.

[Leah]

Originally Posted by fishytime

I like topless

Is that not what tank maintenance is for, Doug.

I would be as well but I have so many tanks running it was suggested to me to cover up.

[SeaHorse_Fanatic]

My main tank (210g mixed reef) is the only topless tank in my place. Once I added glass hinged tops on the other tanks (6 others), evaporation dropped to 20-25%. I used to top up my fw planted every 2 or 3 days, now once a week at the most. My fowlr & ex-seahorse tank is hooked up to a auto-topoff & now the same amount of water will last 3 times longer.

Light is diminished alot with glass tops, especially if you don't clean them constantly.

Thats why my main reef is left topless.