Temperature Fluctuation problem - help

[Playdope]

I'm a little concerned about my tank temperature. The tank heats up quite a bit from the combo of the lights, pumps, powerheads etc.. I run fans on my canopy which keep the temp under control... and I have brought the temp to what I thought was an appropriate range. However, recently... I had to be awake all night, and I saw that the temp had actually gotten up to 82.5 at night. Not only does that seem high, but it seems unnatural that when its dark it gets warmer. Based on what I saw, I decided to let the fans run for a bit longer. The temp is fluctuating from about 78(day)==>82.5 (night).

I am using those NON-digital light timers that they sell at home depot. I thought about adding some more of the pins to turn the fans on and off a few times during the night... but then again, that doesn't seem it would be stable... and I wouldn't begin to know where to have the fans come on and go off. Any thoughts? There must be some way to eliminate such a fluctuation (unless this is how it is for most of you guys not using chillers)?

I stuck in a heater... what should I set he temp at on that? The problem I see with the heater is.. if I set it at like 80, then when the fans go off - won't the temp jump to like 84.5?

Thanks

 

[Anonymous]

Set the heater to 81 or 82...I think you'll have more stability at this temp.

 

[Playdope]

Thanks for the reply...

Here's a quote from an article regarding tank temp...

The most diverse coral reefs are found in a band running from Palau in the Western Caroline Islands through Indonesia (Veron 1986). In this area the atoll water temperature averages around 84 degrees Fahrenheit (28 degrees Celsius) — and probably never gets as low as 80 degrees (around 27 degrees Celsius) — and the salinity on the reef faces generally is in excess of 35 parts per thousands (ppt) (Sverdrup et al. 1942, Brandon 1973). Most of our corals and the associated fauna, including fish, will live best at these conditions (Weber and White 1976).

If this is the case... why do so many enthusiasts (including book authors) recommend keeping tank temperature between 76-82 and s. gravity at around 1.024-1.026? This is the first time I have heard about keeping the temp as high as 84 F.

 

[Anonymous]

Good question.

 

[danmhippo]

The question is not what temp to keep the tank at, but rather if the temp is stable. My tank varies about 1 to 2 degrees from day to night. But if the swing is greater than 4-5, I would be concerned. I have seen tanks that were kept in mid 80's and still do fine. But, that I feel is like walking on thin ice.

Are you using canopy? If yes, My guess is when the lights and fans are off, all the heat gets trapped in the canopy and radiates back to water surface.

I would increase surface agitation by pointing one or 2 powerheads towards the surface. Surface agitation will increase evaporation, and will help pull down water temp quite significantly. I would also keep fan on 24/7. Set the heater at 81. I think this should help stablize your temp swing.