Double checking - return pump from sump/fuge-Refugium-3reef Forums

Marty · 04-07-2008, 10:51 AM

Ok, I just want to make sure this is right in my own head. I have an overflow box that has 800 gph flow. I plan on using a 1/2" ID tubing to the sump. My return is also 1/2" ID do I need slightly higher gph return pump or slightly lower? I'm sure it's slightly higher, but as often as I am wrong. I don't want to chance buying the wrong return pump. lol Thanks.

missionsix66 · 04-07-2008, 10:55 AM

I believe the general rule of thumb is to double GPH with return pump. 600 gph overflow/1200 gph pump.

Marty · 04-07-2008, 11:05 AM

Quote:

Originally Posted by missionsix66

I believe the general rule of thumb is to double GPH with return pump. 600 gph overflow/1200 gph pump.

10-4 Thanks. Karma.

Brandon1023 · 04-07-2008, 11:28 AM

Maybe I'm wrong, but that doesn't sound right. You don't want your return pump to be pumping more than your overflow can handle...it would overfill the tank wouldn't it?

If you have an over flow that drains 600gph, and a return pump that can return double that in the same hour, it seems to me like you would be in trouble there.

Are you sure the roles aren't reversed? Maybe it's that you get a return pump that does half of what your overflow can do? I would think that no matter what (be it 1/2, 1/4, whatever) you want a return pump that doesn't return the water faster than your overflow can drain it....

......color me perplexed.

Marty · 04-07-2008, 11:56 AM

Quote:

Originally Posted by Brandon1023

Maybe I'm wrong, but that doesn't sound right. You don't want your return pump to be pumping more than your overflow can handle...it would overfill the tank wouldn't it?

If you have an over flow that drains 600gph, and a return pump that can return double that in the same hour, it seems to me like you would be in trouble there.

Are you sure the roles aren't reversed? Maybe it's that you get a return pump that does half of what your overflow can do? I would think that no matter what (be it 1/2, 1/4, whatever) you want a return pump that doesn't return the water faster than your overflow can drain it....

......color me perplexed.

The reason you want one that pumps more is becaue you are fighting gravity to get it back up. Also you should regulate flow with a ball valve in the retun line after the pump.

Brandon1023 · 04-07-2008, 12:45 PM

Quote:

Originally Posted by Marty

The reason you want one that pumps more is becaue you are fighting gravity to get it back up. Also you should regulate flow with a ball valve in the retun line after the pump.

LoL trust me gravity has little to do with it in that situation. Especially when we're talking about a mag drive that has a 13' head height (like a mag 7) before it shuts off. Even so, going with a mag 7 again (700gph), if you're pumping it up about 4 feet like me, than it's still pushing 480gph. So if you have an overflow that does half of your return pump, which would be 350gph in this example, you're still gonna overflow the tank unless you're pumping it up at least 7 or 8 feet.

Regulating the flow with a ball valve tends to wear down the longevity of the pump, too.

Marty · 04-07-2008, 12:50 PM

Ok, so with a 800 gph OFB I should be using a 900 gph pump with an in-line regulator valve I should be ok? I'm only pushing 6'x1" of water back up.

Brandon1023 · 04-07-2008, 02:44 PM

If you're pushing it up 6 feet then yea I would believe you will be fine.

missionsix66 · 04-07-2008, 04:29 PM

Hey Marty, I have a 600gph cpr overflow. The pump I use is a mag 12(1200 gallons per hour). There are alot of factors to consider when setting up. 90 deg. elbows reduce head dramatically, head height, diameter of pipe that you are using, pre-filters etc. etc. etc.. I have never had an issue with it overflowing. If you'd like more details in regards to my set-up let me know.

Marty · 04-07-2008, 04:35 PM

Quote:

Originally Posted by missionsix66

Hey Marty, I have a 600gph cpr overflow. The pump I use is a mag 12(1200 gallons per hour). There are alot of factors to consider when setting up. 90 deg. elbows reduce head dramatically, head height, diameter of pipe that you are using, pre-filters etc. etc. etc.. I have never had an issue with it overflowing. If you'd like more details in regards to my set-up let me know.

Thanks guys. This is more complex than I was expecting. lol

Here is what I am looking at doing right now. My over flow box has 800 gph and it has a 1" bulkhead. So to eliminate elbows I was planning using flexible tubing down to a Y fitting to add flow control of intake to my fuge. For the output to tank I was looking at a 900 gph pump up 6' with a ball valve for flow control and a 3/4" flexible tube up to the tank. I'd like to stick with flex hose to eliminate elbows and to make replacement easier. Is this enough data to let me know if I'm on the right track? Thanks.