# Tank GPH



## Chris&Nancy (Dec 25, 2013)

So for a 150g freshwater tank with a wet dry sump. Do I really need a pump bigger than 1000 gph? 750's seem to be the threshold of when its starts to get expensive. Should I just go with the 1200? The sump will be under the tank more than likely.


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## coralbandit (Jul 29, 2012)

I just switched a couple of my pumps(mag 24 and a blueline 55xd) over to jebao DC 12000.The price was right,they are SILENT, and digitally controlled for speed so you don't throttle the water flow(like with a ball valve) ,but actually control the amount of electricity you use.6 speeds!Digital! On full they use 1/3 of the electricity of my mag.No heat transfer either!
jebao pump parts - BuyCheapr.com


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## jrman83 (Jul 9, 2010)

The size you need is a comparison to the amount of water you have coming into the sump. For ex. if your overflow is 200gph, then the pump needs to be at least that...add in the loss you get from the length of return line and you will more than likely need in the 250gph range (not actual figures). You have to figure pump loss and you need to know the flow rate of your overflow.

You want the pump to keep up with the water coming in and also maintain a level in the sump so the pump does not go dry.


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## Chris&Nancy (Dec 25, 2013)

jrman83 said:


> The size you need is a comparison to the amount of water you have coming into the sump. For ex. if your overflow is 200gph, then the pump needs to be at least that...add in the loss you get from the length of return line and you will more than likely need in the 250gph range (not actual figures). You have to figure pump loss and you need to know the flow rate of your overflow.
> 
> You want the pump to keep up with the water coming in and also maintain a level in the sump so the pump does not go dry.


That is why I am asking! I am designing the tank system as we speak. I hear people that say 10x the capacity per hour, people that say 3 to 5x the capacity per hour and some say 6x?? I am fine with buying a 1200 gph pump. But if I only need a 750 to satisfy the bio load of the 150g tank. What should I use? 10x? 5x? 3x? This is just a simple fresh water with gold fish and a rock bass.


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## susankat (Nov 15, 2008)

With the waste producers your planning on I would go 10X


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## coralbandit (Jul 29, 2012)

The pump runs the whole show, not the overflow.The overflow limits the amount of circulation.Few ever exceed their overflow capabilities.The overflow will allow as much water into the sump as the pump provides,it can not flow faster.Your sump will not run dry unless the overflow can not keep up with pump,in which case the water will be all over the floor Having a pump that is adjustable(electrically) is new and a great advantage.For most they use a ball valve to control the flow if necessary.
The pump needs to rated higher than the flow you want as head pressure needs to be accounted for.Head pressure is the resistance from pumping up hill in a narrow tube.For many pumps large tubing is required to obtain the pumps max flow.Also if using pvc or otther hard pipe every 90 degree elbow is considered 1' of pipe towards total head pressure.
I'm running the same DC pump on both my 180(with filter in basement) and 120 with filter only 5'below tank.They are both on full(3000 gph @0 feet) and both tanks have two mega overflows maxing at 1400 gph.I would opt for the highest flow you canafford and achieve as it can easily be tuned down,but increasing usaully requires pump replacement($$$).


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## jrman83 (Jul 9, 2010)

Come to think of it I never really gave too much thought into how much water I turned over, but then again I never do. My wet/dry was rated for a 200g tank, going on a 125g, and with an Eheim 2080 as secondary filtration rated for a 300g.


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## Chris&Nancy (Dec 25, 2013)

Guess 1500 gph it is. I am planning a 1" overflow on each end of the tank. I might even make my sump to have 2 separate media areas with a central return area. Then I can shut off one overflow while I service that side.


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