850 gph, too much?

[Onefish-twofish]

My question is about the pump used to push the water up from the sump. the pump im looking at is used, rebuilt and near here I live so ild like to buy it, its 850 gph. By cliffs article on sumps I need about 725 gph, I think. Tell me what you think. Three feet of head(distance between sump and tank) at least two 90's two 45's, one check valve, ten gallon sump, 29 gallon tank. I'm scared to put too much power on this as it will cycle water through the sump faster, and dont know much if it will be too much current. Not sure what the head rating on the pump already is.

[Brhino]

I don't know a lot about the flow rate calculations, I'm just getting into it myself... but I do know that if the flow rate on your pipe is too high, you can put a valve on the output and adjust it down.

[ibuyen]

It would work, and you could use the check valve to decrease the gph too.

[Cliff]

You'll be fine.

Assuming your pump has 850 gph at 0 head height, your actual flow through the sump and tank will be closer 400 gph. Depending on your skimmer, you might want to adjust that a little. That can be easily done by plumbing in a bypass to divert some of the flow from the return line back into the return pump compartment. I don;t like using valve on return pumps as that cause a lot of excess and avoidable ware and tear on the pump, but that's my preference tho.

http://saltwater.aquaticcommunity.co...umbing-basics/

[Cliff]

Forgot to post a pic of a bypass.

On the return pump in the bottom right hand corner of the pic, you will see I have tee'd off three lines from the return pump. One line goes to a media reactor, one line goes up to the tank, and the last one just let water flow through back into the same compartment of the sump, almost in a endless loop. That reduces the flow back up into the tank and is adjust by using the ball valve on the bypass line

[Onefish-twofish]

I don't know a lot about the flow rate calculations, I'm just getting into it myself... but I do know that if the flow rate on your pipe is too high, you can put a valve on the output and adjust it down.

Not entirely sure what you mean Brihno, by flow rate on the pipe being too high, Are you saying that 850 gph is too high possibly for 1/2 inch. that 1/2 inch is not big enough to pump 850 through without additional stress on the motor. I'm asking because I feel like I missed something somewhere lol.

I see on Cliff's Article about plumbing basics that 1/2 in is suited up to 840, at a given pressure, but that it has a maximum flow of 1260. Is this to say that in order to pump that much, you have to exceed 100 psi? This may be irrelevant because I think the fittings for the pump are 3/4,but I like to ask ?s so I understand. I like to be in the ball park, not outer space when doing something worth while

Thanks for all your responses and help

BTW Cliff, you're awesome as always

[Cliff]

I think Brhino was suggesting that if the flow rate war too high for your liking, or if you want less flow than 850 gph, then you could slow down the flow rate by using a valve.