Backwash

Leaks in the pool, plumbing, filtration system, skimmer, ...
Finding & repairing swimming pool leaks.
Gary Lee

Backwash

Postby Gary Lee » Fri 27 Apr, 2012 14:32

Following backwash, red georgia clay can be seen coming into my pool through all three inlets (seems to be more coming in through the inlet directly inline with the skimmer and filtration system). Dying my liner, steps and all of the fixtures brown, the clay stops coming in through the inlets after the pool runs in the filter position for a while and the chlorine will eventually bleach everything white again (after a week or so). If there is any leak, it is not very noticeable (not too much more than would be expected from evaporation - maybe 1/4" in three or four days in the Georgia sun). After the pool bleaches clean, backwash again and the problem starts all over. I'm assuming, as the clay can be seen entering all three outlets, and the pool does not appear to have a major leak (at least while filtering), that there is possibly a leak inside one of the pvc fittings and that the flow is reversed on that fitting in the backwash cycle. Again I am only guessing, but it seems that this would occur somewhere between the skimmer and the Vari-flow valve. The problem worsens after rain and lessens if I wait a good while (a couple of hours) before starting back up in the filter position following the backwash. I know I'm not crazy and know that there is alot of burried pvc and glued joints in a 17 x 37 inground, so I'd like to have a better understanding of what may be happening. I know from past experience that you can cut the pipe - plug the inlets/outlets and perform pressure tests, but man, I'd much rather have a logical place to begin. This has been happening for several years - I would have expected any loose fittings to have completely come loose, but again other than knowing that backwashing is reversing the water flow back through the sand and out of the pool (and I have a valve that closes the waste line between the filter and the ground), I'm not real sure of technically how the plumbing is effected during the backwash cycle. I run my chlorine up to bleach the discoloration, but know i'm killing liners! (and obviously backwash as little as possible), but WHEW WHAT A PAIN!


ChuckGeo
Swimming Pool Wizard
Swimming Pool Wizard
Posts: 97
Joined: Fri 16 Jan, 2009 16:31
Location: Atlanta, GA.

Backwash

Postby ChuckGeo » Fri 27 Apr, 2012 15:46

It sounds as though you may not be "rinsing" after backwash. You are correct in that backwashing reverses the flow inside of the filter, which stirs up the debris that the filter has trapped and flushes it out the waste line. After backwashing there is still a little dirt in the filter that will go back to the pool when you restart the filter in the "filter" mode. To prevent this blowback, after a 3-4 minute backwash set the backwash valve handle to the "rinse" position and run the pump for 30 seconds to flush out the filter ("rinse" puts the filter in normal filter mode, but the water coming out of it goes to waste), after rinsing you can go to "filter" and shouldn't see any dirt at the return fittings in the pool.
Chuck
Owner, Superior Pool Services
25 years leak detection experience
Gary Lee

Backwash

Postby Gary Lee » Fri 04 May, 2012 08:53

I don't rinse all the time - if that's it, I'll owe you big time - there is just so much clay though - it seem too much for normal filtration. I'll rinse the bijeemies out of it though. Thanks for responding. Work a pool company AND respond to [b]all these folks - WHEW ! You need an ATTABOY!

Return to “Swimming Pool Leaks”

Who is online at the Pool Help Forum

Users browsing this forum: No registered users and 0 guests