What's heating my tank.

[pseudorand]

My inkbird says my tank is at 81.0F even though it's set to 78. The room is at 70F and it's in a basement (very stable temp, no outside light). Could my lights and pumps be generating that much heat?

Tank is a 120g+20g sump/fuge. I have:

• 4 powerheads
• a fluval 401 canister
• A sicce syncra 3.0 return pump
• 4x lumia 5.2 leds that get to 30% max around noon with a 13h total photo period
• a cheap LED matrix on the fuge that does a 15h photo period.
• Acrylic and glass covers on tank and sump (rather than screen, which would allow more evaporation and the associated cooling)

I've double-checked with another digital thermometer on the other side of the tank and it reads 80.0F. I've also moved the inkbird thermometer to the extent the cord allows, but it doesn't change the reading.

The good news is it's steady as a rock and not too hot for life. But I can't imagine lights and pumps maintain 140g of water at 11F above the room temp. And I don't like not being in control of such things.

 

[KrisReef]

Pumps will add heat, ime.

 

[X-37B]

In my 120 and 40 breeder sump I run no heater during the summer.
House is kept at 75° tank runs 80-81°.
Winter house is kept at 70° and tank runs 76-77°.
I run a small 150 watt heater and tank runs 79-80°.
I run 4 powerheads in tank. Sump has skimmer, carx, return pump, small powerhead and small carbon reactor.
I have a cheap 6" fan blowing on the surface of the sump when lights are on that keeps temps down from lights.
Currently run 8 T5's 4" off the surface.
I run all Tunze equipment.
Many pumps transfer quite a bit of heat to the water.
My system has about 6-7°'s of heat transfer so your system has about 4° more due to different equipment.
Total system water is about 120 gallons total in mine.

 

[pseudorand]

Thanks for the point of comparison.

Two of my powerheads are Hydor Koralias, which spec at 5.5W.

5.5W * 3.412141633 BTU/hr/W = ~12 BTU / hr
1 BTU = 1 degree F / gallon
12 BTU/hr * 2 powerheads / 140g = .17 def F / gal / hr

And that's only part of my heat load.

I have no idea how to calculate heat loss, though I suspect if I measured how much my ATO was adding I could get a rough guess. At any rate, I guess pumps and lights keeping the tank 11 deg F / above room isn't totally out of the ballpark.

Now how do I bring it down (not that I really need to, but...). I suspect stuff growing in the powerheads biases their energy usage towards heat instead of flow. I'll give them all a good soak in vinegar and see how much that drops the temp.

What brand/model fan do you have, and can you recommend it as quiet?

 

[X-37B]

Its a 6" clip on not 10".
Got it at home depot $10.
Pretty quiet.
It will drop my tank about 3°. Down side is it increases evaporation. I went from 1 gal a day to just under 2.

 

[KrisReef]

@pseudorand
FYI, You mentioned using vinegar for descaling powerheads and pumps which has been implicated in cracks and failure of the magnetic impellers due to chemical properties of vinegar cleaning action.

Lots of folks recommend citric acid.
Link to a recent R@R thread on the citric acid to use HERE!

I don't have a link to the R2R threads on vinegar chemistry vs acid but they changed my vinegar bath habit. FYi
Kris

 

[Homebrewer]

Thanks for the point of comparison.

Two of my powerheads are Hydor Koralias, which spec at 5.5W.

5.5W * 3.412141633 BTU/hr/W = ~12 BTU / hr
1 BTU = 1 degree F / gallon
12 BTU/hr * 2 powerheads / 140g = .17 def F / gal / hr

And that's only part of my heat load.

I have no idea how to calculate heat loss, though I suspect if I measured how much my ATO was adding I could get a rough guess. At any rate, I guess pumps and lights keeping the tank 11 deg F / above room isn't totally out of the ballpark.

Now how do I bring it down (not that I really need to, but...). I suspect stuff growing in the powerheads biases their energy usage towards heat instead of flow. I'll give them all a good soak in vinegar and see how much that drops the temp.

What brand/model fan do you have, and can you recommend it as quiet?

I bet it is the Hydors. I replaced 4 Hydors with two Neros about 18 months ago. My temps went from being constantly higher than desired to rock steady with my heater doing its intended job.

 

[SMSREEF]

I replaced my heater when my tank was getting up to 83degrees. But that was not the culprit.

It turned out to be my powerhead.

 

[Greg P]

I'm assuming you're aware your covers are insulating the water to some degree.
Just curious why your sump is covered? If you have an ATO try running the tank for a couple days without the cover.
If your sump is in the stand run an exhaust fan to push warm and moist air out and draw cooler room air in.
If it's outside the stand, or your stand is open, run a fan over the sump water.

I use a controller for my sump fans. They drastically reduce the runtime on my chiller.

 

[Water Dog]

Get a mesh lid for the tank and remove the lids on the sump. Evaporative cooling can’t happen effectively with a tank all buttoned up the way yours is. Between the pumps, powerheads, fuge light and display lights, you’re trapping a ton of heat in your system with those lids.

 

[billwill]

Lids on your tank and sump are the issue. It’s like the sun shining through your car windows in a parking lot. And yes, pumps add heat unless they’re not in the water.

 

[BlennyTime]

Just to add, having a hard cover on the tank can interfere with oxygen exchange as well, which can stress fish and corals.