Water Pump causing temperature hike?

[Wallace]

Hi,

I am helping someone to start up a new 110G acrylic aquarium. I had recently moved a water pump from my home aquarium to this new one (upgraded my pump to a bigger one), and on the new aquarium the water temp jumped from 72 degree to 86 in 1 day. There is not even a heater in the aquarium so we can rule out heater mul-functioning. The pump also felt hot after its been running for a couple hours.

Now the strange thing is that before I moved it, that exact pump had been working in a different (60G) aquarium for years, and I have to put 2 heaters in that aquarium to keep the temp there above 76 degrees. The sump of the old aquarium is also in the basement (as compare to inside the stand), so the pump had a much higher head pressure (15-ft head vs. 4-ft head) than its current setup. If I understand correctly, less head-pressure = less resistant = less amp draw = less heat??

So, anyway, at this point I am kind'a stuck... can anyone think of why the pump all of a sudden runs so much hotter? This is the exact pump in question:

http://www.marinedepot.com/md_viewItem.asp?idproduct=CP7111

Thanks!!



Wallace

 

[dskidmore]

Have you cleaned this pump lately?

How cold is your basement? Could it be your old system just had a lot of heat loss to fight?

 

[malkore]

pumps will heat the water, but that's an awefully large spike. I would look at all other sources too...lighting, warmer than normal room temp, faulty thermometer.

 

[JRagg]

Abnormally large temperature rises (across the pump) can be a sign of a pump failing, but unless it is making more noise than normal and/or vibrating more than normal I would probably rule that out. I agree to check differences in ambient room temperature, lighting levels, etc.

Did all of the tanks in question have tops on them? Open topped aquariums are generally cooler due to evaporation.

And now for a question for my own ignorance. Is acrylic a better insulator than glass? If so then that could account for some increased temperature.

 

[Wallace]

Thanks for all the reply, I think the combination of them may have caused the increase. The basement being cooler and have much better ventilation certainly can explain a lot, plus now that I think about it, the "heated" water (in the old setup) have to travel around 30ft of plastic tubing to reach the tank on first floor, maybe it was able to cooled down during that travel. The old sump also have much more surface area for evaporation.

Also, I called Poseidon and they said these pumps are WATER COOLED (!!!) and that it is normal for it to heat up the water a few degrees. But they said it shouldn't be more then 2-3 degree, and he tell me to install a fan inside the cabinet.

Anyway, we did the following:

1. I opened the pump and cleaned the impeller, there are some nasty gunks over it.
2. We removed the top lids from the tank.

Now the temperature stays around 82 degree with the light on (it was 86 with the lights off). I could shave another degree if we leave the cabinet's doors open. But regardless, 81-82 degree is still higher then I would like it to be, but I guess it is tolerable for a FO setup?

Oh and we did verified the temperature with 2 different thermometer.

Thanks!!



Wallace

 

[dskidmore]

But regardless, 81-82 degree is still higher then I would like it to be, but I guess it is tolerable for a FO setup?

Just make sure there's enough O2. If you've got a skimmer, all will be well.

 

[Wallace]

Yes there will be a skimmer in about a month (haven't moved it yet), and the tank has very good surface water movement from the return for O2 exchange. We also plan to substantially "underload" the tank with very few fish, so I think we will be OK.

Thanks!



Wallace

 

[malkore]

ahh, with the added explaination about 30 feet of hose..yeah, I can totally see that much exposed surface area allowing the water to cool off before hitting the tank/thermometer.

 

[afishyonados]

Are you forcing the intake through any 90 degree elbows? Restrictions such as these may raise temperatures as well. The stand should be well ventilated, especially if the skimmer pump will be housed in there as well.