Canopy Fans

[gibson981]

I just purchased 2 cooling fans to place in my canopy. I can't put them on the ends of the canopy to blow across the length of the display because the air flow would be blocked by the reflectors. So, I put them in the front panel of the canopy, one sending air across each bulb (they are 250w 14k Megachromes run by 2 Ice Cap electronic ballasts. Because of my limited space in which to place the fans, they are both within 5 or 6 inches of the bulbs. Will that be ok? Or, will they melt? Also, 5 hours after the bulbs go out, and the diplay temp reads 81.5 F. Should I leave the fans on 24 hours per day? Or only when the lights are on?

[SALT WATER CRAZ]

Its hard to say if the fans will melt or not. :rolleyes: A diplay temp of 81.5 F is not to bad. But it is geting close to the hot side for my likeing. The big thing is that the temp is not swinging to fast. You could put a fan blowing on your sump to help you cool the tank down some to.

[qfrisco]

That fans are to the side of the lights, right? If so, I think they'll be ok. The light (and most of the heat) should be pointing downwards, and the bulbs shouldn't be directly in the line of fire. My canopy fans are a similar distance from my lights, blowing in, and they've been fine.

I've also found that in the summers, I need to run my fans 24 hours a day to help cool the water sufficiently while the lights are off. In the winters, I just run them when the lights are on.

[bzotter]

I agree, if the fans are off to the side, they shouldn't come close to melting. I would run them only when the lights are on, especially if you're temp only goes up to 81.5 cause you'll burn a ton more water if you run them 24/7. If you have to in order to keep your temp down, then do it, but try not to it'll make more of a hastle for you to keep refilling the evaporated water more often.

[gibson981]

The fans are in the front panel of the canopy. I did that because the bulbs are perpendicular to the front of the tank and the reflectors go down pretty far on the sides. The fans would be blowing on the side of the reflectors. This morning at 8AM, 4 hours before the lights came on, the temp was 78.7. The fans came on 2 hours before the lights and stayed on until 2 hours after the lights went out. The lights ran from noon until 9PM. When they went out, I checked the temp and it was 81.5. That's a 2.8 degree swing from 4 hours before the lights came on to the minute they went out (13 hours). Is that too much of a swing if I want to eventually keep LPS, SPS, and some clams?

[qfrisco]

That swing should be fine, as long as it is stretched out over a 24-hour period. My tank goes from 78 to 81 and everyone (LSP, SPS, no clams) is fine!

[bzotter]

I agree. That temperature swing is just fine over the course of a day.

[Canarygirl]

Is it advantageous to have the fans blowing air in to the canopy rather than blowing the hot air out? Or some of each?

[roadcrew]

i would point the fans inward because an outward fan would be drawing salty moist air from the tank. that wouldnt' be good for the motor.

[carlisimo1969]

Fans blowing in with ,holes in the top above the fixtures works great. Fans will last longer, heat takes shortest route out of the canopy.