Pressure Problem

[ballen]

New here - hoping for some help.

Have a 20K gallon in ground pool just opened. Pressure last year at sand filter was about 12 to 15 PSI. It is now only 3, barely able to vacuum. Tried a drain king to clean out skimmer line to no avail. A little air in pump basket area, not much. Pump impeller looks clean.

Here is the kicker - I seem to get more flow at the skimmer when in waste mode than in filter. Don't get a pressure reading unfortunately when in waste or recirc mode. Any ideas would be much appreciated.

[Watermom]

Have you backwashed your sand filter?

[PoolDoc]

membership upgraded.

[ballen]

Yes, backwashed several times. When running in filter mode, the pressure is only 2 to 3 PSI. If the filter was clogged I would expect the pressure to be higher.

[vinper]

you put drain king in your skimmer . acid probably not goodfor it . if good pressure in waste mode still works ,so look for the blockage inline . does it dump alot of water during backwash good flo?

[ballen]

Had a pool company here yesterday. They blew out all lines with a blower, inspected multi valve, still no idea. Get good flow on backwash or waste, very low in filter or recirc mode.