heating a 90 gal

[jck9]

i have a 90 gal and i have been using a 250 watt stealth and a hydor inline 300 watt. temp was fairly stable within 1-2 degrees. i wanted to remove the inline so i bought another 250 stealth. i waited to put he second stealth in until i got my RKLite hooked up. it has now been almost 24 hours and the heaters havent turned off. i have the temp set at 78.3 and it will turn the heater on when it drops to 78.2. the temp stays at 78.1-78.2. are the heaters not strong enough? i figure 500 watts should be enough to heat the tank. also where should i put the temp probe? right now i have the temp probe in the overflow and the heaters in my refugium. sump is a 55gal. return in the middle and fuge on right skimmer on left. fuge was the only place deep enough for the heaters. thanks for any help
john

 

[THE ROOK]

how do you know they haven't turned off? My stealth's don't have lights. I only use them for water changes.

Couple of thoughts:

1. Make sure both heaters are set to about 80*. Best to verify in 5 gallon bucket with a quality thermometer. This will also tell if one is junk.

2. Give yourself a 0.5 degree. That's how I have my controller set & i'm able to maintain my temp with a 350 watt tit. tube heater. I keep my probe in the display & the heater in the sump. This can get you in trouble if you forget to turn the return pump back on. Been there.

 

[jck9]

i was saying that the heaters havent heated the water enough to have the controller turn them off. i have felt them and both are warm to the touch. i just got home from work and checked them and the temp was 78.4 and the controller turned them off. ill just keep an eye on them tonight and see if it drops below 78.3.
john

 

[swegyptian]

For a reference point I had a 500 watt heater and it stuck on and raised my 125 with a 40 sump to 94 degrees when the house was 70. So you should have plenty of juice.

 

[THE ROOK]

As I mentioned, also try giving the tank some room to move. Your only giving the tank a 1/10 of a degree to move before the heater comes on. I have mine set to come on at 78.4 & off at 78.9. It has worked very well for me.

I'm not really sure how others set their controllers.

 

[jck9]

it seems to be staying put now. guess it just needed to level out or something. thanks though
john

 

[airdog67]

I have one 150 watt heater in my 90 gal and it will heat my tank to 95 if I want it to. IM not sure what the problem is with yours though, sorry

 

[jck9]

its good now. i have it set to turn on now when the temp drops .4 degrees. thanks guys