Suction side leak only when filter is active?

[diesel13]

My situation is this. Upon opening this year I noticed some leakage in what I think is the suction side. When I would switch my 3-way to the skimmers it would fill with about 10% air. It has worsened and now the pump runs but can only fill half the basket area. The strange thing is that when I bypass my DE filter the pump can hold its prime. There are still bubbles but its definitely better. I think its suction side because there are no leaks at all anywhere around the equipment or exposed pipes. The air in the intake tank also suggests it. I've done the surface leak tests with the hose but no luck. Any suggestions are welcome.

Pentair 1.5 hp pump
30K gallon gunnite
DE filter, 2 skimmers, 2 returns

 

[duraleigh]

Welcome to the forum
When you do not bypass the filter, what is the psi?

 

[diesel13]

Thank you very much!

My apologies, the pump gauge broke last year and I just installed a plug and oring.

 

[diesel13]

So I installed a new gauge this morning. When its going through the filter, it reads about 28 psi. When its bypassing the filter, it reads about 17 psi.

 

[sktn77a]

28 psi seems a little high (my pump pretty much poops out when it reaches 26psi). Not sure why this would affect the suction leak, though.

 

[ajw22]

When was the last time you backwashed your filter? Or took it apart and cleaned the grids?

My DE filter pressure is about 20 when clean with DE in it and the flow starts slowing at around 30 psi.

Your 28 psi sounds like a dirty filter slowing the flow.

 

[duraleigh]

Yeah, clean your filter. You should get clean pressure around 10-15 depending on the size of your filter.

I noticed some leakage in what I think is the suction side.

Water leak or air leak? If you noticed (saw) it, it must be water and that wouldn't be a suction leak. Got any pics? Help us understand the issue a little better, clean your filter and we'll work on that leak.

 

[diesel13]

Yeah, clean your filter. You should get clean pressure around 10-15 depending on the size of your filter. Water leak or air leak? If you noticed (saw) it, it must be water and that wouldn't be a suction leak. Got any pics? Help us understand the issue a little better, clean your filter and we'll work on that leak.

Thanks to all. I'll get the filter cleaned and recharged tonight after work.

 

[new-pool-owner]

I have a question. Trying to learn about pools--commenters in this thread are talking about the appropriate pressure, but doesn't PSI depend on what RPM he is running?

 

[Jimrahbe]

npo,

It would if the OP had a VS pump, but it appears that he has a single speed 1.5 HP pump...

Jim R.