Calling all pool owners...I have a problem

I have an in-ground pool with your standard D.E. filter configuration with the backwash valve. I just moved into the house not to long ago. So, I decided that I better do my annual cleaning of the D.E. filter grids. So, in the process of cleaning the grids, I noticed the manifold was cracked a little. Didn't really think anything of it at the time.

Anyway, the insides were completely filthy...like the grids hadn't been cleaned in two years or something. The bottom of the filter was just encased in primarly dirt and some D.E. . So, I cleaned it all up and put it back together.

Added the recommended amount of D.E. through the skimmer back to the D.E. filter. So far...so good. Well, then I notice D.E. is returning to the pool. Okay...I'm thinking the cracked manifold is a problem even though the crack isn't very big. I replace the manifold and vacuumed the D.E. on the bottom of the pool to the filter. Well, then I notice that...after the pump shuts down after the daily run...D.E. is returning to the pool from the main drains and the skimmer...as in reverse flowing through the pump back into the pool through the lines that are normally the suction lines. This is when the pump is off.

I've checked the grids for wear and tear, replaced the manifold, and replaced the o-rings on the backwash valve. I don't think any of those are the problem.

So, I was reading that I may have a leak on the pressure side. The only leak I could find is the booster pump for the Polaris cleaner has a drip leak only when the booster pump is running the Polaris. Otherwise, the booster pump is off and there is no drip. I assume this is a bad gasket where the pump meets the PVC pipe.

At this point, I'm trying to figure out why D.E. is returning to the pool from the lines that normally suck water. Could the drip leak in the booster pump be the problem? I would also assume that, if it were the grids or the manifold in the D.E. filter, then it would be passing back to the pool on the return lines when the pump is running. That doesn't appear to be happening.

So, before I go out and pay some pool service potentially hundreds of dollars to fix something, I am asking anyone on this board with pool experience what they think. Could the booster pump drip leak cause a reverse flow of water whereby the D.E. flows back to the pool through the skimmer and drain.

This really sucks. Normally, a D.E. filter is supposed to collect the D.E. on the grids effectively coating them. I think the previous owner hadn't cleaned the filter in so long that is was so clogged up and he never had this problem in just doing normal monthly backwashes.

Please, pool owners, help me out if you can. I would like to fix myself if possible. Again, the only visible leak is when the Polaris booster pump is running. Sorry for the book.

 

In my pool configuration, the spa overflows into the pool. So, water returns to the pool through the spa jets and pool jets. The pool jets are not showing any signs of bubbles. The D.E. filter gauge pressure is running at 20 PSI...which is normal.

As far as adding D.E., if you take apart the filter and clean the grids, then your basically needing to replenish all the D.E.(obviously) to coat the grids again. If your just doing your standard backwash cleaning of the filter, then this is not going to clean out all the D.E. but should get some or most of it along with the collected debris or dirt.

But, either way, I believe the directions do not distinguish between the two and normally just say to add a set amount after a backwash or annual cleaning. If I add 10 "1 pound" coffee cans of D.E. after an annual cleaning, then I may only add 8 or 9 "1 pound" coffee cans of D.E. after a routine monthly backwash(as some of the D.E. will still be present in the filter). I don't think it is an exact science but you don't want to add too little or too much as this could cause problems. I believe they say that if you add 90% of the recommended amount, then you should be good.

There doesn't seem to be air accumulating in the D.E. filter so, if there is air being sucked into the system, it is not getting in the filter. I know this because when I use the bleed valve...it shoots water instead of air. There is no water leaking out of the waste line indicating a bad o-ring on the backwash valve and bottom seal. There is no unfiltered water that I can tell returning to the pool meaning the water is bypassing the filter due to a bad o-ring on the top seal of the backwash valve.

I may have no choice but to call a pool service. I just thought someone with more pool experience than my few months might be able to give me some ideas on the problem. I can actually see a small stream of D.E. powder flowing backwards from the primary pump strainer basket when this occurs right after the pump shuts down and the clouds of D.E. powder coming from the skimmer and bottom of the pool.

 

No. This is closed during regular operations. It's only open when I'm running "spa only" or I need to drain the spa for some reason(which hasn't happened yet).

 

LOL...I'm trying. Some seal somewhere seems to be failing. Otherwise, the water wouldn't be reversing flow when the pump stops.

Aren't there any pool service people on this board? I know your out there!

 

Is that a "Fletch" reference/joke?

 

Yea...well...Fletch humor aside(which was rather enjoyable), I gave up and set up a service call with Leslie's Pool. I have two leaks I have found around the Polaris booster pump. I guess one would consider that a pressure leak. I'll just throw some money at it and make it go away.

"Bad pool! Very bad! Bad bad bad bad bad! Fix the pool! Nobody come! D.E. in pool!" - Sincerely, Babu