Those w/ MH heat probs, my simple solution..

[MT79]

I was having a big problem w/ heat when the MH's came on in my tank. It started reaching almost 90. After adding more airflow to my canopy, etc. I got it down to about 87, and kept it at 84 at night. I could see my whole tank slowly stressing more and more. I noticed the heaters where kicking on/off, even when the tank was "hot". I put them on a timer so they kick off when the MH's come on, VIOLA high of 83 now with VHO's and MH's going!! Has anyone else tried this as a heat solution?? If not you may want to try it.(2x250MHx2/110VHO over a 55gal. no sump)

[electrikat]

Why would your heaters come on even when the temp was already higher than their settings?

[MT79]

Why would your heaters come on even when the temp was already higher than their settings?

I have no clue. That's why it took me so long to try this LOL. I thought I needed a chiller. FWIW they are both visi-therms, one is a stealth model.

[klam]

Sometimes heater temp control dial are miscalibrated so you would have to compensate for that. My heater is dialed in at 80 degrees but in reality it heats up the tank to 82 so I have set the dial to 78 to get my desired tank temp of 80. On some heaters you re-calibrate the temp dial.

If this doesn't resolve the issue and the heater is still heating when it's not I would look into replacing the heater. I had a viso-therm heater once and one day it stuck and heated my tank above 90 degrees.

[MT79]

They keep the tank at a rock steady temp. when the MH's are off so there is no problem w/ the heaters. They are set at 82 now b/c the lights alone heat the tank to 82-83 I've found-this has been like a science project for me LOL. I should add, it wasn't just one of the heaters kicking on, it was both. The thermostats just don't seem to fair well in higher temps...

[klam]

It just doesn't seem right to me that they would turn on in higher temps.

[ellisz]

I had always wondered that. My tank temp would be 84 and I would go to the sump room and see the lights on the heaters! I always attributed it to the sump being in a different room than the tank but it really should not matter.

My sump will soon be in a unfinished basement so I suspect I will have to heat my water instead of trying to cool it

[MT79]

It just doesn't seem right to me that they would turn on in higher temps.

I know, I hesitated posting this b/c I thought I was missing something. When the water gets warmer than the heaters are set for they still kick on. They just aren't efficient unless they are battling cooling conditions it seems.

My tank temp would be 84 and I would go to the sump room and see the lights on the heaters!

I'm not alone then!

[ellisz]

To add to this, my tank goes to 81.5 at night and I have a 300 watt and a 250 watt heater in my sump.

[MT79]

my tank goes to 81.5 at night and I have a 300 watt and a 250 watt heater in my sump.

And it reaches 84 during the day? If so you may want to try unplugging one or both of the heaters while your lights are on and closely monitor the temp. through out the day. You may be able to cut down on the fluctuations some. You do have a good amount of more water than me, so your lights alone may not be able to keep the temp high enough...just a thought.

[ellisz]

I normally run a fan on the sump to help with temps. I am acclimating my livestock to new MH bulbs so temps are not too bad since the MH's are on for a shorter time.

I used to have 1 heater but switched to 2 to help with swings. I would love to keep my tank at 82!

Once I move the sump, I hope to not need all the fans I have in my canopy either.

[Thumper]

My heater is the same way basically, not to the extent your is but it's not very effecient on shutting off at the right time. I have enough water volume that it doesnt change my temp much during the day but i have noticed it coming on and off during the day with the mh running.

[Jason]

All I have to say is that you have a lot of light on that 55 gallon tank.

[MT79]

All I have to say is that you have a lot of light on that 55 gallon tank.

That's what I intended