Air leak again, I think....

[Outlawhistory]

OK,
have a new pump Sta-rite Max-E-Pro & Jandy valve installed last year. Using a Sta-rite System 3 sand filter. Pool is about 18 years old, below ground fiberglass, 33,000 gal pool.
Had the OUTLET fixed about 3 years ago, crack in the PVC. Leak detection found it, return was OK.
So, this year June 2014, just got the pool open, lots of air in the basket, rolling water and air, lots of air bleeding off in the filter after 1/2 hour.
All connections checked, O rings etc going into the basket, water tested the fittings. I did install a " eye" on the exit into the pool which helped by causing some back pressure but didn't solve it completely.
The pool does hold 4 psi on the pump gauge OVERNIGHT, while pump is turned off and no loss of water in the basket, so it seems to be holding pressure and I assume no underground return leaks.
Pump runs at about 17 psi. with the " eye" causing backpressure, about 12 psi without.

What next ? Any thoughts ? The normal suspects are addressed, right ? Lost.

A bit confused in Colorado-

Thanks

 

[duraleigh]

If you are getting air into the system while the pump is running, you have a suction side air leak. Did you read the article in Pool School on how to address them?

I don't know what you mean by "eye" but I don't think it's relevant....nothing on the pressure side of your system should have any affect.

Not at all sure how you can hold 4 psi on a non-running system????

 

[Outlawhistory]

Yes I did read the section in the pool school, thanks. Eye is a eyelet that directs water flow at the out side, not sure of correct term, it reduces the flow by directing it.
Yes getting tons of air in while the pump is running, as back pressure builds, the water in the basket drops by 1/3. I backwash, rinse then fire up again and it returns to where it was.

With pump off, water level maintains in the basket ( about 90% full) in a sealed air tight condition. Filter holds 3.5 #s on the filter gauge. If I open the top on the pump basket the seal holds till I pull the plastic top off, then seal breaks, water leaves the basket and filter pressure drops to zero.

 

[Outlawhistory]

Just noticed what looks like a partial stream of whitish water coming out of the outlet, causing light foam on the pool surface. Possible foam from oxidation of the chlorine ? Took the eyelet off the outlet too ( under water in the pool), not much change really in the amount of air coming in. Poll has a light amount of foam on it, here & there.
My thinking is if the filter was holding 3.5 # pressure, and pump basket wasn't draining overnight, I don't have a leak underground in the PVC return-
Wish-full thinking ?
May be the last year of a pool, after 18 years !!!!!! yes, frustrated this year.

Thanks-

 

[duraleigh]

If your filter is holding pressure when the pump is off, something must be installed wrong. The circulatory system in your pool is not sealed. Any pressure created by the pump quickly (immediately) drops to zero as the water flows back to the pool.

I don't think that has anything to do with your suction side air leak but you need to figure out why your pool maintains psi....that's wrong.

 

[Outlawhistory]

OK, that's interesting, nothing has been changed except a new pump and Jandy valve last year, makes me wonder- Did change the sand this year, first time in 7 years, but that was straight forward, laterals looked OK and all. Multiport is original... Maybe a bad gauge, but there is pressure still maintained in it when I pop the lid off the pump basket or unscrew a connection fitting, does still have pressure, not much but a little.
Have to ponder this, no clue.

Thanks for the help, I've got an odd situation to deal with now....

 

[duraleigh]

Do you have check valves? They would have to be on both the pressure side and suction side but that might explain the psi retention.

 

[Outlawhistory]

Dave, thanks-
No check valves, did have one on the heater but disconnected that years ago for solar.
We've made a decision, going to pull the pool or fill it in. Why ? Pool was installed in about 1986, fiberglass pool. Have had it for 18 years. No kids, really don't use it anymore, live in Colorado, short season, 68 years old now, rather have grass now. Probably have a leak in the return, 30' run under concrete, pavers etc.
Appreciate all the advice here, good forum.
Thanks-

SJ