Pools, Spas and Hot Tubs - Which speed for new pump?

I just replaced my old pool pump with a VF-3050 pump. I need to know what speed and for how long i should run the pump. I'm not sure exactly sure of the size of my pool. I have been told sizes from 30,000 to 40,000 gallons. It is a inground kidney shape about 35ft long with a built-in spa. At speed #1 it seems the pump is barely on and does not even build up any back pressure on the gauge. Speed #2 defintely is running good and slow and builds about 2-3psi. Which speed and time should i use?

skeeter

why are you using a 2 speed pump? A pool needs to circulate during sunny hours of the day, off at night.

This pump is a variable speed pump, Pentiair VF-3050. It has 4 preset speeds with the ability to adjust the speeds in between the presets. The pump instructions give the different rpm speeds of each setting but not a GPH. I figure somewhere around the two lower settings would be where i want to set the pump for normal filtration. Can anyone who knows this pump and ball park size of my pool help with a setting? How do i determine what to set it for and how long?

skeeter

Oops, Sorry. Actually it is a VS-3050 pump. I can never seem to remember that. Anywho....... the preset pump speeds are 750, 1500, 2350, and 3110rpms. I can't find a graph or chart that translates that into GPH.

skeeter

Ok, i found a rpm-to-Gph conversion chart. Two things i have to now know are the total volume of my pool and the head pressure. Can anyone give me a good head pressure guess?

skeeter

take a look at this link, it has a graph on the last page http://www.pentairpool.com/pdfs/intelliflovfDS.pdf