Debris coming back into pool

[Fiveattripp]

The Polaris does have a booster, but I'm not sure how I would isolate that return. I do believe that it is getting better with the new sand, though I don't know why that would make a difference in that one return. I have attached a picture of the pump set up (oops my profile won't let me post an image). I'm just not sure where to check. There are two flexible hoses on that booster pump. They have never been replaced. Is it possible that there is a pin hole in one of them causing some air? The pump basket has air sometimes and sometimes it doesn't. Let me know if there is a way to post a JPG photo so you can see how it is plumbed. Thanks for any thoughts.

[SunnyOptimism]

Hi @Fiveattripp

Attaching Pictures

For attaching images, try using a photo sharing service like Picasa or PhotoBucket. I use Photobucket and whenever I upload a photo, it generates an embedded image link that I can use on most message board systems. I believe Picasa by Google is the same.

So you have two issues - debris in the Polaris return AND bubbles in the pump basket. Let's deal with them separately as I'd be surprised if they were connected.

Bubbles

OK, so bubbles in the pump basket are almost always the result of a leaky or poorly fitted cover seal. On my brand new pump I was surprised to see that the sealing surface for the o-ring on the pump housing was so rough. I got bubbles too but what I did was use some very fine grit sand paper to smooth out the sealing surface (very gentle, you're not trying to take off major amounts of material) and then I also applied o-ring lube (I prefer pure silicone based, not teflon). This immediately made the bubbles go away. So my first suggestion is to take the o-ring off the pump basket cover and inspect both the o-ring for obvious damage and the pump basket sealing surfaces. O-rings, even those that are well taken care of, rarely last more than a few seasons before they develop micro-cracking in the rubber.

It is also possible that the o-ring was replaced some time ago but with the wrong size ring diameter. This too could lead to a poor seal. I actually up-sized the diameter of the o-ring on my pump basket cover (same ID, slightly larger OD so that the thickness of the ring was greater. It made an overall tighter fitting seal.

If the bubbles keep coming back, then you need to look further downstream from the pump suction line and test PVC joints to see if they have developed any leaks (unlikely but possible). The way to do that is to try to submerge or flood the joint with water to see if that stops the bubbles. It's not easy to do and typically requires two people and some creativity on how to best flood the joint with water.

Debris

Honestly speaking, I think replacing the sand was a bit overkill and probably a slight waste of money. I don't own a sand filter but I do know this - sand is sand and, despite what the pool repair guys will tell you, silicon dioxide can't "go bad". Now a sand filter can get very dirty but the filter media itself, the sand, will never go bad. If your sand filter hadn't been cleaned in years, then I would have suggested a deep-cleaning process first before trashing the old media.

Two of the biggest reasons for sand and debris getting through the filter are deep-channeling of the sand media AND/OR broken or damaged laterals. Less likely, but still in the realm of possibility, would be a bad spider gasket on a multiport valve or a bad seal on a push-pull valve (depends on how your sand filter was installed) but that would present other problems (like water leaking out the backwash line, etc).

It is possible in old media that hasn't been backwashed regularly for deep channels to develop in the sand such that water and debris flows through the media without much filtration. Think of it like a dry and cracked muddy lake bed. Water can easily flow through the channels. However, if you did have deep channeling, I would expect to see debris coming out of all returns unless the booster pump is sufficiently strong enough that it would draw most of the water through that one return and collect debris in that line (possibly at a vertical 90deg elbow buried somewhere).

As you posted, your laterals were fine upon visual inspection and replacing the sand media would have corrected any channeling problem. So you'll have to update us in the long term on if your debris problem is gone.

The only other sources of debris would be from a cracked PVC line somewhere but that is really a remote possibility. Unless the plumber did a lousy installation job, buried PVC piping is pretty resilient. The only time I ever saw a buried PVC break was from tree roots. It was a buried 1-1/2" diameter PVC line for an irrigation system and a nearby tree had sent out some roots looking for water. The roots were literally wrapped around the pipe and cracked it. It was impressive.

Anyway, keep this post/thread going with pictures and updates as I'm interested in how this all resolves.

Cheers

[Fiveattripp]

https://www.dropbox.com/s/u0v04cj1ae...pump1.JPG?dl=0

Thanks so much for the help. I have attached the link to the pump and booster pump. Our Sand was in bad shape...even though I try to keep it back washed and stay on top of the care of the pool. I guess it might have been about 8 years since I changed it. The pool is 15 this season and I changed it once. The water is looking good now. I will do what you said with the basket lid where the O ring sits. It is a new O ring so I don't think it is shot. I inspected the spider gasket last week thinking it might be that. It is in good shape too. Trial and error..I will keep you posted...again Thank you for sharing your knowledge!

[SunnyOptimism]

{Unsolicited opinion}

I think you should replace that T connector with a 3-way Jandy valve so you can isolate/throttle the booster pump and pressure side cleaner line from the main return flow. If a 3-way is too expensive, then you could also just have a simple Jandy shut-off valve (I don't like ball valves because they tend to leak, but that would be an even cheaper option). This way, when the Polaris is not running, you can completely isolate that line. HOWEVER, if your Polaris booster pump is automated or timed to regularly go on and off, then isolating that line could cause the booster pump to dead-head (pulling on a dead line) which would burn out the booster pump.

I say this because I don't like the idea of having that 1-1/2" (?) pressure cleaning line always open to return flow especially with all that flex tubing. If that flex tubing and/or couplers should spring a leak, then you will have your pool water return line open and you'll flood your equipment pad.

Also, I'd very carefully inspect all of that flexible tubing and couplers for leaks. After 15 years, it's entirely possible that you could have a leak there....

{End of Unsolicited opinion}

[SunnyOptimism]

That picture just made me realize something - is that booster pump tied into the plumbing before the sand filter?

If so, then the booster pump that feeds the Polaris is using unfiltered water from the skimmer/main-drains. Therefore, if junk gets past the pump's skimmer basket, then it can easily get sucked into the booster pump and returned to the pool through the Polaris port. That would explain why you have debris coming out of your Polaris return and not any other return. That would also then be a VERY GOOD reason to install a shut-off valve or isolation valve on the pressure side line as you are diverting pool water away from sand filter and right back into the pool. It's a smaller diameter line and there's a booster pump in the way so the flow is going to be small but it still would exist. Some booster pumps don't allow water to pass through them when they are not ON but others do, it depends on the make and model. A check valve with a high spring force after the booster pump would help cut down on the flow of water sneaking past your sand filter.

Of course, if my view of your plumbing diagram is wrong, then ignore the above.

[swimdaddy]

I think you nailed it. With the booster pump on the pressure side unfiltered water water could make its way through and back into your pool. Quick question: could the booster pump be on the suction side of the main pump?

[SunnyOptimism]

Quick question: could the booster pump be on the suction side of the main pump?

No, you should not plumb it that way. Two pumps running in parallel on the suction side of the line would "fight" with each other for water. I don't know the specs of that booster pump but it would likely lose the fight with the pool pump. Also, booster pumps are designed to boost the pressure and flow rate of water already moving in them, they are not really designed to initiate flow on their own. There are other PF users way more knowledgeable about pumps and water flow than me so perhaps they can chime in.

Also, the setup as it is depicted is not wrong per se, it's just missing a critical component - a way to isolate the Polaris line when not in use. It's probably ok to use "dirty" water to run the Polaris since any large size debris will just get captured by the Polaris leaf bag. You could hook the booster pump in on the return side (clean side) of the filter but then you'd have lower pressure water to work with and that might not make the Polaris happy.

Simplest fix, in my opinion, is to add an isolation valve just after the PVC T-connector on the vertical leg so that the Polaris port can be shut off when not in use. This should result in slightly higher filter pressure and no more "junk" coming out of the Polaris port when not in use.