Return Pump Question?

[BlazinNano]

I am going to setup a sump but It can not be under the tank because the sump is too wide for the stand, plus my top off is under there. I am going to build a small stand next to the tank for the sump. My question is I know pumps loose volume when you add height to the plumping. My question is if the plumping is not straight up does it count towards the "height"??

 

[Ladipyg]

Head means at an upward flow...you will loose some volume by going sideways longer but it won't be anywhere near as much as going straight up.

 

[BlazinNano]

Ok has anyone used to big of a pump annd doe anything to slow it down. I have a Mag12. I right now only have a 30 gallon and that is a lot of flow if I am only going to have a head height of 6 feet. Would it be easier to just get a different pump or put like a blow off valve to dump extra water back into the sump????

 

[AZDesertRat]

Head is a combination of vertical lift or height and losses due to pipe friction and fittings or direction changes and reductions in size.

A Mag 12 is way too big for a 30G system even if you restrict the flow. At 6 feet it will still be pumping in the neighborhood of 900 GPH. The wattage will be around 90-100 watts in doing so. Heat will be a big problem is such a small system.
Recirculating some of the flow back to the sump sounds good but is really counterproductive. Centrifugal pumps only draw the watts required to do the work at hand plus some for inefficiencies. By recirculating you are pumping closer to the full 1200 GPH so would consume around 110 watts and generate the 110 watts of heat. A better option, within reason, is to valve to discharge side of the pump so you reduce the output and reduce the wattage since the pumps is moving less water.
I say within reason because this pumps is just too big to do this efficiently for such small flow. You will never get it to operate efficiently because of its design capacity. A better option would be something more like a Mag 5 or Mag 7 although I am not a fan of Mag pumps in general, they are power hogs, run very hot compared to others and are noisy. Eheim and Ocean Runner are two much better choices more suited for what you need, maybe an Eheim 1250 or 1260 or an OR 2500. They are both very efficient, run much cooler and are silent. I tried Quiet Ones and had two literally burn up so will never go there again. Tried a Rio Hyper Flow and had the impeller magnet swell up after a few months so bad it would not turn in the housing, another write off. Had the same problem with a Via Aqua pump too.
I have 4 Ocean Runners in my systems today and some of them are over 5 years old and still chugging away with the original impellers and magnets.

 

[Ladipyg]

I have heard good things about the Eheim pumps as well as the ocean runners. I am using a Mag 18 on my new 120 (the price was right and the tank is in the basement so heat is not that much of an issue). I had the same problem with a Rio Hyper flow and the impeller magnet....I use a large CA (Catalina Aquarium) pump in my fish pond for 2 years straight with no problems. I feel your better off matching the pump to the flow you need so that you don't have to throttle back the pump...I believe it causes premature pump failure in the long run.

 

[AZDesertRat]

Throttling or valving a centrifugal pump in no way reduces its life as long as you do not reduce the flow so much you eliminate or reduce the cooling effect. Most if not all pumps designed to be both submersed or external have water jackets or passages inside the motor so product or process water is fed around the windings to keep it cooled. This is why most of them add the same amount of heat to the tank no matter if they are external or submerged, it makes no difference.
In fact some pumps perform better when you restrict the flow or add additional head as it brings them closer to their best efficiency point on the performance curve.

 

[Ladipyg]

Interesting...thanks for the info....

 

[gflat65]

As has been stated, any Z direction is head pressure (as is any elbow/coupler, etc.-anything that adds friction). There are some head calculators on the web. I don't have any good links, but they are out there. I'm running a Mag 5 on a 40B with a 20L sump and that combo seems to be great. Throttle down the outlet if needed (would be over 13X turnover through sump). You could Tee and send the throttled down water to a fuge or something.

 

[BlazinNano]

i am thinking about adding a 10 gallon to the setup just for a skimmer. that will make the whole setup 58 gallons.....