Minimum sand filter pressure

[mvn]

Hi folks,

have a variable speed pump, which normally runs at 1400rpm on ‘low’. The pressure on my sand filter (actually has glass in it instead of sand) reads 0. When I push the rpms beyond 2000+ I start getting a linear rise in rpm’s to PSI.
My plumbing is super straightforward - 50mm suction side to pump, 40mm into sand filter with one right angle, then return out to 3x pool outlets. No SWC (just a chemistry controller and probe).

I can’t seem to find any guidance on the minimum pressure, is running at a low RPM with the pressure at 0 ok? Or is something else wrong?

thanks in advance!

 

[koffey]

I think you should be able to find this information based on your pump, aka spec sheet or from the manufacture.

However, if you are saying that low, or minimum rpm is 1400 and that is what the manufacture indicates and your psi is 0, somethings wrong. 0 PSI is 0 flow. What is the nominal pressure for the pump?

 

[Jimrahbe]

mvn,

I have a 30 psi gauge and the pressure on my cartridge filter is about 1 lb.

As long as you have good water flow there is no minimum pressure..

Filter pressure is not a sign as to how good your pump is doing, but a sign of the effort is takes to force water through the filter... In my mind, the lower the back-pressure the better.

Obviously, the faster the pump runs, the more water it moves, and the harder it is to push that water through the filter, and the resulting higher pressure.

Thanks,

Jim R.