# Thread: Flow rates and turnover

1. ## Flow rates and turnover

does anyone know how to calculate the turnover of a pool based on pipe size and pump?

I'm interested to know how many gallons water a 1 hp hayward super pump with a hayward c900 cartridge filter and 1 1/2" plumbing can turnover per hour?

Thanks!

This is what I have to do on but not sure of actual turnover as this is based on 2" pipe size and pump flow rate..

2. ## Re: Flow rates and turnover

This is something that Mark is going to have to answer.

Is this based on an existing pool? There are other thing he will want to know like:
Number of suction lines.
Number of return lines and fitting sizes
Filter pressure.
Height of pump relative to water level.

He may be able to estimate a "typical" pool without some of this info.

3. ## Re: Flow rates and turnover

yes this is an actual pool. it's 8,000 gallons. has 2 return jets and 1 skimmer.

the pump house is about 10ft away. 1 1/2 inch pipe.

filter pressure is around 12 psi and pump sits on the pool deck which is where the pump house is. actually his pump is I think 3/4 hp super pump.

Thanks!

pic of pool below..

4. ## Re: Flow rates and turnover

Flow rate is complex to calculate and depends on either knowing nearly every detail of the plumbing, or in making measurements of the pump suction and filter pressure and matching that to the flow curve of the pump.

5. ## Re: Flow rates and turnover

First, the tables you are showing are for the filter and really don't tell you anything about what the pump will do.

Second, it makes a difference what pump is being used. Do you have a pump model#?

Thrid, is there a backwash valve on the filter?

Fourth, what is the height of the pump relative to the water level?

6. ## Re: Flow rates and turnover

Originally Posted by JasonLion
Flow rate is complex to calculate and depends on either knowing nearly every detail of the plumbing, or in making measurements of the pump suction and filter pressure and matching that to the flow curve of the pump.
I just have some people trying to save money on electricity and think running pumps 5-6hours per day is saving them money and is ok when the big costs are aircondition and water heater. I know we need to turn all the pool water over 1 1/2 - 2 times per 24hrs in the summer.

7. ## Re: Flow rates and turnover

Originally Posted by mas985
First, the tables you are showing are for the filter and really don't tell you anything about what the pump will do.

Second, it makes a difference what pump is being used. Do you have a pump model#?

Thrid, is there a backwash valve on the filter?

Fourth, what is the height of the pump relative to the water level?
Hi Mark, its a hayward c900 cartridge filter. there is a drain on it but no backwash.

the pump is a hayward 3/4 hp super pump.

the pump is on the pool deck so I guess maybe 6"-1' above water line.

Thanks.

8. ## Re: Flow rates and turnover

There are two 3/4 HP SuperPumps: SP2607EE (3/4 HP Full Rated) and the SP2605X7 (3/4 HP up rated) pump. Both are labeled 3/4 HP but have different head curves.

Assuming the pump is the SP2607EE (3/4 HP Full Rated), then the operating point is probably near: 55 GPM @ 41' of head. The up rated version would have about 10% less flow rate or around 50 GPM.

9. ## Re: Flow rates and turnover

Originally Posted by mas985
There are two 3/4 HP SuperPumps: SP2607EE (3/4 HP Full Rated) and the SP2605X7 (3/4 HP up rated) pump. Both are labeled 3/4 HP but have different head curves.

Assuming the pump is the SP2607EE (3/4 HP Full Rated), then the operating point is probably near: 55 GPM @ 41' of head. The up rated version would have about 10% less flow rate or around 50 GPM.
Thanks Mark,
41 ft of head is a lot but thats total head? height + distance? I read something on that. I think thats right?

10. ## Re: Flow rates and turnover

Dynamic head loss is determined by not only the length of pipe but also the flow rate through the pipe, pipe diameter as well as the pipe surface roughness so it is not just the length that matters. Plus other components of head loss in plumbing include the friction loss of fittings, valves, filters, heaters, etc. So there are many contributors to head loss.

41' of head @ 55 GPM is fairly typical for 1.5" plumbing.

11. ## Re: Flow rates and turnover

cool thanks Mark. This has always been a blind spot for me. I am mostly so busy with running the biz and salt chlorination and pool management. You made it simple. Thanks I really appreciate it.

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