Return Pump Recommendation Poll

[BeanAnimal]

Originally Posted by MKLKT

Cool to see a reef celebrity On topic, I suppose it also depends on where you live and the temperature balance as removing residual heat from a pump might need to be offset by the aquarium heater (Canadian winters!), could possibly be even less efficient overall. Obviously every case is completely different and it's a matter of understanding your system and its components. Same situation as how watts/gallon still persists even though it means nothing.

Not so sure about the celebrity status, in fact I would venture to say that I rub most the wrong way

You are correct, some folks may miss the added heat from a pump like the T4. That siad, nothing is "free" and in most cases the watts being shed as heat in the pump (heating the water) are watts not used to move water. That is a 140 watt pump that imparts 40w of heat into the water, 20W of heat into the room and 90W of energy into 1000GPH of water movement is likely less efficient (as a system) compared to a 40W heater and and a 90W pump that moves 1000GPH of water....

We can get into complicated scenarios but no matter what, we want our pumps to move more watts per gallon. If we submerge that pump in the sump, we are capturing the heat it sheds anyway and things are a bit more fuzzy. But yes, for external pump users who also have to run heaters, any watts being shed to the room and not the tank are "wasted". In those cases, a submerisble pump is likely a better choice, as ALL of the heat shed has to travel through the water

To add to this discussion in my case for submersible pumps I recently switched a Sedra 9000 which had an impeller issue (unit itself was buzzing) and frankly was too small for my setup anyway for an Eheim Compact 5000+ and love it so far. Having the adjustable flow right on the pump saves the plumbing and head loss from any sort of flow adjuster above the pump.

Yeah, I have not had luck with the sedra, ocean runner, etc.

While the "adjuster" may be convenient, it does not save "head loss" Head loss is, well, head loss. The adjuster works by adding static head to the output of the pump, the same as adding more pipe (friction), more vertical head (gravity), more fittings (friction and turbulance), etc.

At any given head (read "the total resistance to flow that the pump sees") the pump will discharge a fixed amount of fluid. In other words, the pump curve is fixed and not relevant to HOW or what is causing the "head". It could be your adjuster, it could be your thumb over the discharge, it could be the 20 feet of discharge hose, etc. Hope that helps. We just know that for a given backpressure there will be a fixed volume of flow per time.

That said, I am sure that the compact 5000 is a great pump, as most (all?) of the eheims appear to be.