Sump/Return Pump Question

[Frogfan183]

Random question:

So I recently built a custom 29 gallon sump and added an aquamaxx 5 return pump. Since its been running my overall temp has increased quite a bit where the return puts the water back into my display tank. I have a thermometer near the return and another on the opposite corner on the sand bed. The thermometer near the return is near the yellow band (or warning level) and the second thermometer in right in the OK range.

The LFS has mentioned that this return pump typically runs warmer than others and has recommended me buy another pump (a Sicce one). Of course they sell both so I just want to make sure I'm not being taken for a ride. Anyone else have any experience with this? I'm currently freezing my top off water and dropping that in to keep the temp down but I don't want to have to continue to due this.

Also FYI I've pulled my heater out of the DT so I know its not the heater.

Any help is appreciated.

 

[bang guy]

Any idea what the actual temperature is?

All waterflow will increase water temperature. It's the first law of thermodynamics.

 

[Frogfan183]

Its running anywhere from 80-82 right at the return and 74 ish at the opposite corner. I just don't want to have to keep icing it down all the time. If there is a pump that runs cooler I'd prefer to get a new one.

 

[lmforbis]

80-82 is an acceptable temp. Mine runs around 80-81 all summer, 78 in the winter.

 

[pegasus]

I have 5 pumps in the return chamber of my refugium. All five pumps are Danner Supreme Classics... Mag-Drive 12, 7, (2x) 3, and a 2. My tanks temps run consistently between 79-80F. My heaters kick on quite regularly to maintain those temps since I keep the house at 71F during the day, and 69F at night.

 

[2quills]

If the display tank is maintaining a consistent temp I wouldn't sweat it too much.

Many of the newer pumps that use less wattage have gotten a lot better when it comes to transferring less heat. I use a water blaster 5000 on my system and the water temp in my return chamber is virtually identical to the display temp.

Mag drive pumps were pretty notorious for adding heat. I do run one in my sump that filters water in my return chamber through a filter sock and re circulates the water through the fuge.

I don't run any heaters (live in south texas). Between all of the pumps and average house temp the tank stays right around 74-76 degrees most of the year.

I have 3 small computer size fans that are continually blowing air across the surface of the tank which seems to help quite a bit and run leds which transfer like no heat to the tank.

 

[bang guy]

All internal water pumps will transfer 100% of the power they consume into heating up the water. For example, a water pump consuming a constant 250 watts will heat the tank about the same as a 250 watt water heater that is stuck in the on position.

The only ways to reduce the amount of heat transferred are to use an external pump or if you can't do that then a more efficient pump so that it consumes less power for the amount of water delivered. So 2quills comment about newer pumps that use less wattage is spot on.

 

[pegasus]

All internal water pumps will transfer 100% of the power they consume into heating up the water. For example, a water pump consuming a constant 250 watts will heat the tank about the same as a 250 watt water heater that is stuck in the on position.

The only ways to reduce the amount of heat transferred are to use an external pump or if you can't do that then a more efficient pump so that it consumes less power for the amount of water delivered. So 2quills comment about newer pumps that use less wattage is spot on.

It all boils down to efficiency. An efficient pump will use less energy and run cooler, while an in-efficient pump creates wasted energy. Wasted energy is thermal energy. Computer power supplies are an excellent example. A PS that operates at 75% efficiency creates far more heat than one that operates at 85%. This is due to the energy that the lesser efficient PS is wasting. Wasted energy creates heat. Get an energy efficient PS, or in this case a pump, and heat generation will go down.

 

[robertmathern1]

I have to agree with the others as long as the tank is consistant at those temps I would not worry about it. Just keep it in mind down the road when you need another pump but for now I would not spend the money in another pump.