Bubbles, Filter Drains Down - normal?

[ekim]

When my pump shuts off I get lots of bubbles in the system. It seems as if the filter is draining out into the pool.

If I leave the pump running non-stop for a few days, I have zero bubbles in the pump housing.

There are no check valves in the system that I can see.

Should the filter hold water, or at least most of it's water when the pump is shut off?

 

[mknauss]

The filter and pump should remain full. You have a leak somewhere. Might be on the pressure side. Any water showing up? If not, when you turn off the pump, listen for air being pulled in. Leaks can seal under pressure with water but then suck in air when under vacuum.

 

[ekim]

The filter and pump should remain full. You have a leak somewhere. Might be on the pressure side. Any water showing up? If not, when you turn off the pump, listen for air being pulled in. Leaks can seal under pressure with water but then suck in air when under vacuum.

I could hear the air being pulled in. Found a wet plug on the filter valve (I guess a plug for a pressure gauge?) and a water "bubble" on the PVC pipe coming out of the pump. Addressing these seems to have fixed the problem.

Thank you for the quick reply and excellent debugging suggestions.

 

[mknauss]

Great. You need a pressure gauge on your filter. Otherwise you will not know when to clean it.

 

[ekim]

I think there are two possible places to put a gauge. On the valve, and on the top. The valve appears to be a small NPT fitting. The top seems to be something sealed with an O-ring. Is one preferred over another?

 

[mknauss]

Pressure gauges typically come with a 1/4" NPT male fitting. It also needs to be measuring the pressure before the filter media.