Huge temp drop with the addition of a fan

[Jamie]

Hi all, I just thought I'd share this. Since the beginning of this tank (my 150),I've struggled with maintaining an acceptable temperature. I bought 300 watts of PC lighting from AH Supply, but considering that I have about 8 inches of height in my canopy, and the fact hat it has an open back, I didn't think it would cause a temperature problem. But the temp would never go down...I ended up blaming it on my return pump, a Custom Sealife Velocity T4 (which has gotten a bad wrap in regards to raising the temp of tanks). Awhile ago I bought a fan but it wouldn't fit under my canopy...so instead I aimed it over my sump and return pump, hoping that it would make a difference. No joy though. Lately the temp has been hanging around 86* F. Finally, last night I just got a little too irritated with the situation and got a bit more ambitious. I disassembled most of the fan and managed to get it to fit under my canopy. When I went to bed, the temp of the tank was 86 degrees. When I woke up this morning, it was 78! My lights have been on for about 4 hours now and the temp really hasn't changed. I'm so excited. I am going top set it up so that the fan comes on with the lights. I also bought another fan...(they're only 6 bucks at home depot)...They're quiet, and once taken apart a bit...are only about 6 inches in diameter, so they fit wonderfully. I still can't believe it...I never thought that 300 watts would increase the the temp of a 150 gallon tank by 8 degrees...wow!

[joe schmoe]

I've got 302 watts on my 125. Even with the homemade fixture sitting right on top of the tank (which leaves the reflectors about 1/2" from the top glass) temps only vary by a degree or two. You may want to consider redesigning your canopy to something similar to AH supply's homemade version.

http://mysite.verizon.net/res7weom/fixture.jpg

Note: I don't recommend making it as short as I did. I'm going to eventually redo mine with twice the height, and a hinged front panel with lexan at the front so I can see any flowers or above-water growth...then a removable cover over the lexan so I don't have to have the room lit up by the lights.

[Jamie]

I am happy with the design and look of my canopy. I actually have about 6 inches between my lights/reflectors and the water (there's no glass between my lights and the water). As well as about 3/4 of an inch between the top of my canopy and the reflector (for circulation). Now, with the fans, I have no complaints. Despite the fact that the back of the canopy is open, the temp would still build up under the hood and drastically affect my tank's temp. I guess that 3/4" oak is a good insulator...but like I said, with the fans now, absolutely no problem. I'm sure I will evaporate a lot more water...but I really don't care about that.