Internal Pump Efficiency

[straydum]

i've been thinking of having a small pump to power my phosphate reactor and managed to dig out a boyu submersible from my store. the ratings are as follows,

BOYU submersible pump SP-700 5W 230 l/h

to test the heat it gives out, i placed the tiny pump in a mug and ran it for about 2 hours, together with a thermometer. its rather shocking that the final reading the thermometer showed was 36 degrees! i understand that the higher wattage the pump is rated, it would generally give off more heat but to 36 degrees is wayyy to high.although i do run a chiller, i don't wish for such a tiny pump to be putting off that much heat. reading up on RC lead me to understand that it is due to the inefficiency of the pump that leads to the heat.

basically, a pump running 10w but only utilizing 5w worth of energy to push water would mean the remaining 5w would equate to heat, sound, and movement (vibrations)

just checking with everyone here for a recommendation on a pump which is not powerful and won't put in that much heat into the water?

i'm considering between an Eheim 300 Compact Pump (150-300 l/h), a Hydor Pico Evolution 200 Pump (270 l/h) and a Tunze 5024.04 Universal pump Mini (150-300 l/h). hopefully someone could shed light on to which pump would give off the least heat

and just wondering, is there any difference with a Eheim 300 Compact Pump and a Eheim 1046 Universal Pump (except that one runs internal and the other both internal and external)? both pulls the same wattage and flow but the price difference is huge!

thank you

[FuEl]

Why not just Tee-off from your return pump?

[straydum]

i just tried that and it works! thanks fuel

was initially afraid that it wouldn't be strong enough cause my return already goes to the tank, chiller, and now the reactor

[vurbul]

My view...... its a tiny pump in a tiny mug, of course it going to be hot. There's no where the heat can go. Try a big pail or a bathtub.

But you found the solution already, so