Water pump question

dabeyta · May 10, 2016

Hello. I have been looking for something like this post but just couldn't find it. So my question is. How can i tell what type of pump would i need to push water? For an example is i have a water pump in a sump, and say the tank is 8 feet high. How could i tell what pump would work for me? Thank you all for your help in advance.

Oceansize · May 10, 2016

I have this question too, but I doubt you'll get a worthwhile answer until you provide your system volume, both for your DT and sump. Pumps are rated by how many gallons per hour they move.

dabeyta · May 10, 2016

Oceansize said:
I have this question too, but I doubt you'll get a worthwhile answer until you provide your system volume, both for your DT and sump. Pumps are rated by how many gallons per hour they move.

I'm not even there yet. I am trying to put everything together before I buy anything

saltyfilmfolks · May 10, 2016

You need to calculate your desired return rate based on overall water volume. 80g x 5x (return rate) = 400gph pump.
Head loss is the term for how much pressure is lost in the pipe. That is based on the diameter of the pipe and fitting, and the length of the pipe.

Google aquarium return rate calculator. youll find one thats good.

dabeyta · May 10, 2016

saltyfilmfolks said:
You need to calculate your desired return rate based on overall water volume. 80g x 5x (return rate) = 400gph pump.
Head loss is the term for how much pressure is lost in the pipe. That is based on the diameter of the pipe and fitting, and the length of the pipe.

Google aquarium return rate calculator. youll find one thats good.

Thank you. Is there such thing as an over kill on the pump? If I were to put a valve on it and don't allow it to fully push what is was attended to. Could I damage the pump?

saltyfilmfolks · May 10, 2016

theres a link on this page.

Thanks Melev!
http://www.melevsreef.com/node/710

jonh2765 · May 10, 2016

Some pumps will give you a head height for shutoff .

saltyfilmfolks · May 10, 2016

dabeyta said:
Thank you. Is there such thing as an over kill on the pump? If I were to put a valve on it and don't allow it to fully push what is was attended to. Could I damage the pump?

yea and its loud, built up back pressure heat too. DC pumps are the thing now. Variable flow. or just get close w an AC pump and go with it. Jeabo DC (1200,4000,5000,12000 lps) is the hot low budget ticket.
Return rate is opinion, 10x is oft recommended but man its FAST. most seem to go 4 to 7x.
too fast a flow will first, make a jet out of your return(think firehose), second, not let poop settle in the skimmer sump and fuge.

dabeyta · May 10, 2016

saltyfilmfolks said:
theres a link on this page.

Thanks Melev!
http://www.melevsreef.com/node/710

What a great article. Thank you so much.

AZDesertRat · May 10, 2016

It does not harm an aquarium pump in the least bit to install a valve on the discharge side. In fact it makes many pumps more efficient as it brings them into a better place on their pump curve. They run cooler and consume less electricity since they are doing less work.
Restricting the suction side is a different story though as it can cause cavitation and starve the pump.

saltyfilmfolks · May 10, 2016

AZDesertRat said:
It does not harm an aquarium pump in the least bit to install a valve on the discharge side. In fact it makes many pumps more efficient as it brings them into a better place on their pump curve. They run cooler and consume less electricity since they are doing less work.
Restricting the suction side is a different story though as it can cause cavitation and starve the pump.

I assume my probs were from lower GPH and "less expensive"

smaller pumps. under 1000 gph.

AZDesertRat · May 10, 2016

It all has to do with Bernoulis Theory and The Laws of Affinity which deal with hydrodynamics and centrifugal force. Put a Kill A Watt meter on the pump and you see the power consumption or watts go down as you throttle the valve and the pump runs cooler since it is not working as hard.

saltyfilmfolks · May 10, 2016

AZDesertRat said:
It all has to do with Bernoulis Theory and The Laws of Affinity which deal with hydrodynamics and centrifugal force. Put a Kill A Watt meter on the pump and you see the power consumption or watts go down as you throttle the valve and the pump runs cooler since it is not working as hard.

Yup, i get that. I use a split piece of 12/3 sjo so I can use my amprobe on stuff. when I throtled back the 700 gph pumps, they really pretty much just died. well screamed and then died.

I got what I paid for.

What do you think of the dc pumps? Jeabo included. Torque changes with dc, so I was going to throttle back and then set the return. Cheap underrated power supply is my fear.

AZDesertRat · May 10, 2016

I have not tried the dc return pumps yet. Love my WP-25 wavemakers though and getting a RW-4 for my nano soon. I have been 100% happy with my WaterBlaster HY-5000 so have not switched to DC for the return.
Years ago I did a big write up for Reef Central on 10 or so popular AC pumps at the time which was quite detailed. I used a flow meter, 0-10 psi calibrated pressure gauge, gate valves to add head, digital thermometers, a Kill A Watt Meter and even a dB meter. Some did well, others did not.