Pump Flow / GPM

[ITR]

Hi, again, folks. Since it's getting ready to warm up here...I'm finally taking a stab at determining my GPM and turnover time. I have a 1.5HP Whisperflow pump and the pool is 10,300 gallons. Based on the calculations from the spreadsheet here it says my GPM is 86. Does that sound right given 20 PSI filter pressure and 2" piping?

If so, it's saying my turnover time (on high) is just under 2 hours. Can that be right?? I have been hearing people say 6-hours....8-hours....10-hours....etc. 1.99 hours seems low compared to all of these numbers.

Thanks in advance!

 

[jblizzle]

Why are your taking a stab at this? Turnover rate is really pretty meaningless. See: Determine Pump Run Time

 

[ITR]

Probably more because I am an engineer by nature and profession (well...a manager of Engineers now)...and out of curiosity.

I don't know how many articles I read saying you should have at least one turnover per day....so that's why. Plus my electric bill is a bit high so I'd like to calculate the minimum and not just go with some average of four hours as I don't know if my pool is average, below, or above. Seems like it's a waste of money to have the pump running longer than it should (not to mention still fighting pH problems and wanting to cut down the aeration time as well.

 

[jblizzle]

One of the moderators runs his pump for 30 minutes a day. No one says you need 4 hours. That is just a starting out point.

If you search the forum you can find the thread that links to the studies that were the basis of that article.

A turnover is often much more pump run time than you need.

 

[JasonLion]

The whole number of turnovers thing is just completely wrong for a residential pool. That is a rule from commercial pools that makes sense in that context, but does not translate to residential pools at all. For a residential pool, the most important factor is clearing surface debris, which is mostly about time, and has little to do with pump size relative to pool size. If you want to find the shortest possible runtime, you can find it experimentally easily enough. Try shorter times and see what happens. At some point stuff will start accumulating on the bottom more quickly than before, which is a clear sign you don't have enough pump run time.

 

[ITR]

Interesting...by surface debris are you talking about the debris at the waterline or the debris on the surface of the floor? Just curious...as the PB aimed the jets towards the top of the water to create a rippling effect, which I would also assume would clear the debris on top of the water more quickly. After the scaling issue I had, i just don't want to get into any problems by playing around with the numbers only to create a problem that is going to cause more work/issues down the road.

 

[jblizzle]

He means on the surface of the water. I would lower the jets some to avoid the rippling which will aerate and raise your pH.

Scaling has nothing to do with the pump run time, that was due to improper chemistry.

 

[ITR]

It was actually caused by improper application of the interior (they did not acid wash after application)...I haven't had a scaling issue since. I was just using that as an example....not saying the scaling will come back because of the pump. Sorry...I'm a noob when it comes to pools.