Is this cavitation? Pump makes grinding noise on zone 2.

[FLSteve]

Recently bought a house (built in 2010) with sprinkler system. It is supplied by a community well. It has six zones that all "work", in the sense that the heads/rotors pop up and spray, but some zones cause the pump to make a terrible noise (particularly zone 2).

The pump is a Sta-Rite DS3HF-01 and the valves are Hunter SRVs. I've went around to all the heads and made sure they were clear of debris and had filters.

Here is a video I took of the problem:

The video starts with zone 1 running. I then switch to zone 2, let it run a bit before switching it back to zone 1 around 1:30.

 

[Valveman]

Steady 40 PSI is good. It looks like some of your zones are larger than others and the large zones draw more water from the supply line that it can supply. Put a pressure gauge on the suction line. If it gets close to zero you are drawing more water than the incoming line can supply.

 

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[FLSteve]

Put a pressure gauge on the suction line. If it gets close to zero you are drawing more water than the incoming line can supply.

Unfortunately, I’m not able to put a gauge on the suction line easily. I’d have to cut out some pvc.

One thing that I’ve noticed is that when my pump runs, I see bubbles in my sediment filter. Between the well and pump looks like this:
Well
Metal pipe
Check valve
Sediment filter
Pump

the check valve was recently replaced by me, it was chattering so I thought that it may be failing and causing my issue. It didn’t help.

the sediment filter is one of those clear jar looking filters with a mesh screen. It’s been cleaned and checked for leaks.

I’ve tried the “pour water over joints” trick to see if I can figure out where the bubbles are coming from, but no luck.

 

[Valveman]

The o-ring on your filter is probably letting air in. O-rings are made to seal pressure not vacuum. The filter itself will cause extra restriction on the suction line and should be moved to the discharge side of the pump.

 

[FLSteve]

Where is a video of the bubbles:

 

[FLSteve]

The filter itself will cause extra restriction on the suction line and should be moved to the discharge side of the pump.

Would the best place for the filter be between the pump and valves?

 

[Reach4]

Would the best place for the filter be between the pump and valves?

After the pump, for sure.