Having trouble stabilizing temp...

[Splach]

Hey guys,

I have been having trouble stablizing my temp. The heater I have seems to be doing weird things and so I hooked it up to my Aqua Controller last night. I have also created a routine to turn off the MH lighting if the tempurature goes 1 degree above where my heater turns off, however I am curious just how tight of control I need to have on my temp before I put the LR in (I don't have a chiller).

Casey

 

[shanekennedy]

1 degree sounds very tight. your lights might be going on & off quite a bit. i have my alarms set for +/- 2.5 degrees with 80 being the setpoint.

 

[Dazz]

At night my water goes to about 77 degrees (on cold days) and during the day up to about 81. I havnt seen any problems with it.

 

[hdtran]

How are you measuring your temperature? Is it an in-tank thermometer, or a paste-on-the-outside? The paste-on-the-outside, in spite of being more expensive, are much less accurate than the floats-in-tank (or sinks in tank ) alcohol thermometers.

With your 190g of water, you've also got a huge thermal mass (heat capacity, for you thermo freaks), and it would take a very large amount of power to swing that temperature...

I don't think your MH (if they're vented and have fans) would be increasing your temperature all that much. I would suspect that your temperature reading is out of whack, more than the heater is being flaky.

 

[Splach]

I think I tracked the problem down to having my x-10 controlls setup incorrectly so my AquaController was turning off the heater instead of one of the... Well anyway... I screwed up. I am using a Neptune labratory grade tempurature probe.

For the past 24 hours my temp swing has been at 1 degree. 78.2 when the MH went off and 77.2 when they came on. Since we use A/C in the house so that our house is between 65 - 70 degrees year round I think I am in good shape for skipping the chiller. The MH are vented through an attic vent so they don't even seem to heat up the cabinet air (for 800W of MH and 220 watts of Actinic I think thats pretty good).