Hot tank !

[IslandHopper]

90 gallon display, 40 gallon sump (well... probably only 25 gallons of water though)
Mag950 return pump
Reef Oct skimmer with a OTP-3000 (40W) pump
2x Koralia 1500 powerheads
2x 108W LED fixtures (with fans, well ventilated)



With everything running, the water temp goes to 84F degrees !!!

So I've got the skimmer off, and the temp is dropping. At the very least, that'll have to go on a timer and only run part-time... but the plan is to put corals in this tank, so I really need to be able to control the temp with the skimmer running full-time.

I may put a small fan in the hood and see what help I can get from evaporative cooling, otherwise it seems a chiller may be in my future.

Any other ideas for keeping it cool? (Before I pop $500 on a chiller.)


(Yes, this is a brand new set-up ... a few fish have been in for less than a week now after cycling the system ... meaning it's not a new problem in a previously stable tank, but an ongoing effort to stabilize a new tank.)

[Airgoose2222]

From other threads I've read, it could be the sump pump running very hot and heating your water. I would check that out first. If it's the culprit, then you may do some research on pumps that don't run as hot and replace it. Should be cheaper than a chiller

[Ingy]

Any chance of replumbing your return pump external to your sump? That would remove around 60w of pump heat.

[IslandHopper]

Originally Posted by Ingy

Any chance of replumbing your return pump external to your sump? That would remove around 60w of pump heat.

That's exactly what I ended up doing ... took the 90W pump out of the water and replaced it with an Iwaki 1140 gph pump.

Had to drill the sump without tearing it down... then re-do all the plumbing... then re-do it AGAIN because the hard plumbing (pvc) between the sump bulkhead and the new pump caused a really LOUD vibration! Replaced that with 1" hose and it now runs nearly silent!

The temp dropped steadily overnight after the install and now hovers right around 78.5 ... I'm much happier with that!

And it was much cheaper and less overall complexity than a chiller.

[Gti_Leo]

you don't need pumps that big you could get away with a mag5

[IslandHopper]

Originally Posted by Gti_Leo

you don't need pumps that big you could get away with a mag5

I want the flow rate... I also have a bigger than "needed" skimmer ... I plan to have it fairly heavily stocked with fish and corals a year from now ... I'll need a lot of flow through the sump to keep things clean.

[Gti_Leo]

thats the thing you don't need heavy flow through your sump. if its not a wet/dry system then to hig ha flow lowers the efficiency of your skimmer, if you have a refugium it also slows its efficiency down also.

my general rule is 2-3 times the turno over rate through the sump and you can always place a power head in the refugium to get a bit more tumbling and thicker chaeto.

[IslandHopper]

All depends on the design of the system ... I designed mine for this type of pump/flow.

I'm not arguing against your position, just stating that, in THIS specific case, the entire sump system is designed with that size pump in mind. (The entire flow goes through mechanical filtration, some of it gets diverted to the skimmer, and only a small, but adjustable, portion flows through the refugium.)

[Noturaveragereefer]

I have the same problem in my 37g bf...I don't know where it's coming from I have the heater off now though...(even tho it was set at 75) I have two filters and two Power heads.

[IslandHopper]

Oh well ... now that outside temps are in the 90's (I'd prefer to keep my indoors around 80) and high humidity, the water temp is back up over 82 degrees. (That's the point I have the lights and skimmer programmed to shut off.)

So a chiller has been ordered... time to fix this problem for good.

[54seaweed]

you could try this they do wonders for me best part under $50.
Fluorescent Aquarium Lighting: Cooling Fans

[IslandHopper]

Originally Posted by 54seaweed

you could try this they do wonders for me best part under $50.
Fluorescent Aquarium Lighting: Cooling Fans

While I'm not running fans, I do have quite a bit of airflow around my sump right now ... so I'm just not sure if that would provide enough cooling. I'm more interested in getting rid of the hassle all together.