Better Temperature Control

[yorkcoparamedic]

Hey everyone I have a 30g reef setup that I am currently trying to keep the water temp as close to 80F as possible. I am using one 150W submersible heater that seems to be doing a decent job at keeping the temp above 78F at night when then lights are out. Once the lights come on the water temp goes up to around 81.5F give or take a couple of tenths. Here is the lighting and scheme used.

Coralife Power Compact Aqualight with one 96W dual tube 10K, one dual tube 96W Actinic Blue, two moon light LEDs. The light is about 3 1/2 to 4" above the water and also has two fans when the 10K are on.

Heater set to 76F (any higher will cause water temp to be to high when the lights are on).

1200 = Actinic on and moon lights off. (Temp about 78.5F)
1300 = 10K's on. (Temp about 79F)
1700 = Temp about 80.5F
2000 = 81.5F
2200 = 10K's off.
2300 = Actinic off and moon lights on. (Temp tonight was 81.5F) (last night was 82F and adjusted the heater down some).

Is this normal to have such a variation in the temp? Or is there some way to control this better?

The surrounding air temp in the room is kept at 68 to 70F 24/7 and there is no direct flow of outside air that come in contact with the tank. Would the addition of a second heater at the other end of the tank work to keep the heat more dispersed throughout the night?

And I do not have a chiller installed to bring the temp down just in case your wondering. What does everyone else do?

 

[SkiFletch]

The problem is not the heater, its your high-powered lights heating up the water The heater's thermostat should tell it to be off during the day when the lights are on, thus not putting heat energy into the tank. However your lights are putting heat energy, and infrared energy (converted to heat) into the tank water. Solution, increase surface agitation and place a fan blowing across the surface of the water. This will speed up evaporation but will also keep the temp lower.

 

[yorkcoparamedic]

Thanks. I will add a small fan and re-direct a powerhead toward the surface to see if that helps. The heater has a red light on when its heating and I do not see this during the day.

 

[yorkcoparamedic]

Bought a second power head just to increase surface movement. Works well, I got a .5 to .75 degree F change for the better. I have it set to the same timer as my white lights, it only runs when they are on.

I am going to try the fan now and set it up the same way. Hopefully that will help some too. I was thinking, I have a couple of older fans from computer power supplies. If I hook them upto a 12VDC power supply and hook that to the timer as well it just might do the trick. I only hope that they move enough air.

 

[SkiFletch]

Fans and evaporation really work wonders for tanks with heat problems. My fans (which are AC fans) are also on the same timer as my lights... Works great keeping my temps down