Intelliflo VF flow rate for good skimmer function
I just installed a Pentair IntelliFlo VF variable speed pump. I have it set for one turn of a 25,000 gal pool in an 8 hour period. I start the filter cycle with Feature 3 set at 75 GPM for 1 hr. That gives me about 48.8 GPM for the remaining 7 hours of filter cycle.
I get modestly acceptable surface movement and skimmer suction at 75 GPM, and almost no movement at 48.8 GPM. Pentair tells me that these flow settings are way too high and that 30-35 GPM should provide me with good skimmer function.
I ran a number of tests with Pentair tech support guy on the phone. He thinks my skimmer line is either partially blocked, or the 3-way valve is not fully opening the skimmer line. Seems to me that would just require a higher pump speed to develop the set flow rate to overcome the additional pressure drop. I wasn't convinced the Pentair guy knew what he was talking about.
I replaced a single speed 2 HP Whisperflow. That pump really pushed the surface and the skimmer worked great. To replicate the surface movement using the VF, using the VF manual function, I determined my 2 HP pump was probably putting out about 120-130 GPM; VF is incredibly loud at these flow rates and uses about 25% more energy than my 2 HP.
Pool is 32x16, one skimmer on the middle of 32' side, bottom drain, and 4 return jets. The 3-way valve is set for about 80% skimmer and 20% bottom drain.
What flow rate do you need for good surface cleaning and skimmer function? Any ideas on what's wrong?