Lighting evaporation exposure

[bromion]

Hi all,

I have a 400W MH bulb mounted about 8-in above the water surface in my 55gal reef. The water temperature goes way up when it's running (the bulb is cooled by 4 computer fans, so that temp doesn't get too high). Currently I cover the aquarium with glass, about 2-in above the water surface, but I am thinking of removing this and putting in a fan to cool the water.

The question is, should I put in additional glass/acrylic between the bulb and the water surface (say, closer to the bulb)? Is it dangerous to expose the lighting components (bulb and mount) to the evaporate in general?

The aquarium is covered by a full hood made of black acrylic. How does one deal with heat and evaporate transfer out of the hood? Venting fans, drilling holes, nothing, etc?

Thanks for advice!

 

[AquaReefer]

I would have something between the light and tank just incase. If water can splash up and hit the bulb it could shatter and fall into your tank, and thats the last thing you want. I have around 230watts for my 20g and everyday i need to put about a gallon of water back in. I have a glass top but dont like it on there, thats when i lose a lot of water. I have 2 PC with covers so the bulbs are not exposed. If you are really serious and are looking for coral or already have it i would look into a chiller. Whats all in the tank? How long has it been running?

 

[bromion]

Tank currently has about 60lb LR, 1.5-in sand bed, a number of Zoanthans, some small soft corals, shrimps, crabs, worms, algae. 4 JBJ SP1800 powerheads, bak-pak skimmer with rio 600, heater to control the overnight temp drop.

I do want to keep corals and clams. Temperatures near 90F are way too high, coupled with the drops to 85-ish or lower when the light is off. I would rather not use a cooler, since they are overall expensive and should be unnecessary if my lighting practices are correct.

 

[fishfreek]

The glass over the tank is trapping the heat from the light causing high water temperatures. I have a 250W MH over my 20 gal and my tank temp rarly gets over 84F. I have egg crate over the tank between the light and the water and a large 120MM icecap fan pulling cold air into the canopy. Expect at leat 1 gal a day in evaporation with proper water movemnt.

 

[DragonForce]

The glass over the tank is trapping the heat from the light causing high water temperatures. I have a 250W MH over my 20 gal and my tank temp rarly gets over 84F. I have egg crate over the tank between the light and the water and a large 120MM icecap fan pulling cold air into the canopy. Expect at leat 1 gal a day in evaporation with proper water movemnt.

Exactly, I replace about 3/4 of a gallon per day with my 175w MH. I have no glass or anything between the ligh and water.

That glass is also probably preventing your tank from proper gas exchange.