I have a pentair TR-100 and a pentair Inteliflo VS (3hp) pump. I have installed a Flovis check valve / flow meter between the filter and heater. I think the pump is capable of 140 GPM. I'm sure this is the max under optimal conditions, but it will peg the flovis at 100 GPM pretty easy. I believe the max flow for my valve, filter, & heater is 125 GPM. My questions are, what is the max GPM I should ever run under any circumstance? What is the optimal GPM for the sand filter to work best? I understand slower is better for the filter. If I understand right more flow is slightly more efficient for heating than less flow. Is higher GPM better for backwash/rinse? If so, how much? I have 2" sch40 everywhere. Thanks for the help!
Optimal GPM flow rate for filtering and backwashing.
- Thread starter crashxx
- Start date
I run my VS pump at 1100 rpm for filtering, skimming and making chlorine with the SWG. And 1950 rpm for solar heating. It uses 150 ways and 550 watts respectively.
- May 3, 2007
- 16,833
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
It is better than at max flow rate. At max flow rate, you can push the debris all the way through the filter. But in general, for a sand filter, it would be best to stay below 15 GPM/sq-ft if possible.
A Pentair TR-100 is 4.9 sq.ft. filter The flow rate is 15-20 gpm/sq-ft, so between 75 and 100 gpm for backwashing would be fine. For filtering the slowest you can get away with is suggested
Ok, I think I'll set my max speed to 100 gpm. i will use that for back washing. I figure I'll run 80 gpm to heat, then set the other two speeds for filtering at 15 gpm and 40 gpm. Does that sound reasonable?
- May 3, 2007
- 16,833
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
- May 3, 2007
- 16,833
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
According to this: http://www.pentairpool.com/pdfs/MasterTempAUOM.pdf
Lower limit is 40 GPM so why not run at that instead?
Lower limit is 40 GPM so why not run at that instead?
I thought I had red it is slightly more efficient, at least on the heat/gas side, to run a higher GPM.
- May 3, 2007
- 16,833
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
The heater is a little bit more efficient at higher flow rates while the pump is a lot more inefficient at higher flow rates. If you compare the two, the pump probably has the biggest financial impact.
I meant "read".
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Got it. So would it be better to run at the minimum GPM or bump it up 10 - 15 GPM?
- - - Updated - - -
Got it. So would it be better to run at the minimum GPM or bump it up 10 - 15 GPM?
- May 3, 2007
- 16,833
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Heater manufactures generally put quite a bit of margin into their minimum numbers so I think it is very safe to run close to the minimum. Plus there are safeguards built into the heater such as pressure switch and thermal switch that will trip if the flow rate is too low.