Temperature Control

[Eryl Flynn]

Ok we have a 125 gallon tank, and we thought the temp was pretty stable but LFS suggested less change from night to day. Was getting to 81.6 day and down to 77.4 in the morn when the lights would be turned back on. We have Coral Life Actinic lights, 2 36" rated at 196 watts each which gives us about 3 watts a gallon. I have a heater in the wet/dry to keep the temp up at night. I am gonna run it at I think 77 degrees since they tend to heat more than what the setting says. We had it at 74 for the fresh water and it ran at about 78.

What else should I do to try and keep it stable? I thought about a chiller but those things are VERY expensive and we just spent alot getting the salt water gear to get it going.

 

[Al Hobby]

If you can mount a fan that will blow across the top of the tank or sump it will lower the temp of the water several degrees. I have my fans set on timers so they switch on / off with the lights.
With a fan, you will have a faster rate of evaporation so some type of auto top off system will help keep the salinity stabe.

 

[doc_slick]

I'm just curious where you are taknig your temperature measurements at. In my professional life I have seen thermometers that are hig up in the tank itself and the lights actually heat the glass of the thermometer higher than the actual water temperature and give off false readings because of the thermometers proximity to the lights. Also i'd like to know the composition of your aquarium and the ambient temperature that your home thermostat is normally set to. Let's try to determine if it is actually your tank water that is shifting or something else that is causing the fluctuation before you spend more money on something that you might not need.

 

[doc_slick]

I'm just curious where you are taknig your temperature measurements at. In my professional life I have seen thermometers that are hig up in the tank itself and the lights actually heat the glass of the thermometer higher than the actual water temperature and give off false readings because of the thermometers proximity to the lights. Also i'd like to know the composition of your aquarium and the ambient temperature that your home thermostat is normally set to. Let's try to determine if it is actually your tank water that is shifting or something else that is causing the fluctuation before you spend more money on something that you might not need.

 

[Eryl Flynn]

That is not the case, BUT I think the thermometer is bad. The lights were off with just one heater in a 125 gallong tank for 8 hours. The house was about 70 no registers near the tank. The chemical sticker thermometer said 74 but the in tank one said 85.7 How the hell can one little tube heater keep a 125 gallon tank and wet dry at 15 degrees over room temp for 8 hours? NO WAY.

Once I convince the girlfriend her thermometer is not working (she doesn't beleive me yet) I think I can stabilize the temp, the question will be where to stabilize it at. 78, 80, 81?

 

[Anonymous]

I would strongly suggest you get a third "opinion" on the temperature. The sticker thermometer is not good either, I can tell you from experience, esp. if you have a acrylic tank.

 

[PeeJ]

you can get cheap cooking thermometers at target or wal mart for like 10 bucks...accurate to the 10th of a degree.

 

[Anonymous]

>... accurate to the 10th of a degree.

Those thermometers are good starts, but don't take the reading to 1/10 of a degree.

 

[Eryl Flynn]

I am vindicated!!!! She took it to work, her father tested it and it is reading 10 degrees high. He recalibrated it and so that should solve that issue and I can get the temp nice and stable. The tank is glass, and the thermometer on it is not accurate, but it isn't that inaccurate. We were gonna break out the old submersible mercury/glass one she had but don't need to now.

Think I should shoot for 81 degrees or should I go lower?

 

[doc_slick]

I keep my show tanks at about 78 degrees. I keep my coralline grow out tanks at 81 degrees as it seems to work better for that. Use your judgement though.

 

[doc_slick]

I keep my show tanks at about 78 degrees. I keep my coralline grow out tanks at 81 degrees as it seems to work better for that. Use your judgement though.