DE Filter backwash plumbing issue

[Jtowne99]

We've been in our house for a year and just discovered that we may have a plumbing issue where the backwash doesn't go to a sewer, but instead recirculates to our pool. We have a Hayward DE filter and a Starclear cartridge filter. The pool inspector didn't notice anything out of the ordinary last year, but when we hired him for pool school later, he was puzzled as to why we had the filter cartridge. Said it was overkill and didn't have an answer as to why some clean DE shot into the pool when he showed us how to backwash. We used the pool very little last year and only backwashed once, with the same result. This time dirty DE shot into the pool. We assumed we did something wrong in the backwash process, and forgot about it because we drained the pool shortly after (CYA was above 160 ppm when we inherited it).

We had the pool acid washed and the DE filter totally cleaned by a pool service company this spring in preparation for refilling the pool. The pool guy set the DE filter up for us, but also couldn't figure out why we had the cartridge filter. He never checked or cleaned it, and we didn't think anything of it or to check it ourselves, being pool newbies. So we backwashed a couple weeks ago after slamming the pool and black water shot into our pool this time. We called a third pool service company, who discovered the DE clogged filter cartridge when we told him what happened. He thinks there are 2 possibilities: either the original installer cheated and didn't run the backwash line to the sewer, or the pipe collapsed or clogged, so the cheaper solution was to install the cartridge to catch the backwashed DE. The problem is it's a huge mess to clean every time as I have to clean the filter and drain the filter container to get the floating DE out, which goes all over the ground, makes a mess that's hard to clean up, and poses a health hazard (I'm still trying to sweep it up and may try the shop vac).

The new pool guy mentioned getting a separator. I've been looking online and Hayward makes on that looks like we could swap for the cartridge filter. Does this seem doable? I've attached a picture of our set up, which may or may not help.

 

[Richard320]

That setup makes no sense.

It's time to find out where that third leg (or is it an optical illusion?) on that check valve goes. Maybe it needs to be teed into the return or maybe it goes to the sewer. The backwash line needs to be routed to a sewer or into a hose connector so you can discharge the dirty water. And then the cartridge filter can be sold on eBay or craigslist.

I use cellulose in my DE filter and just backwash onto the lawn. It's just highly refined sawdust and will biodegrade.

The only possible reason I can think of to do it that way is if the multiport leaked. Instead of replacing the spider gasket (pretty simple) some genius decided to filter it and return it to the pool. As you've discovered, that cartridge filter can't hold all the DE.

 

[jblizzle]

Is that a plain old cartridge filter or is that a DE separator that would catch the DE and dirt and keep the water?

 

[Jtowne99]

It's a cartridge filter. I was hoping to swap it for the separator. Here's the view from the top. The current pool guy says we should cut off the stub and shove a hose down and see if water comes out somewhere. This is the best advice we've gotten.

 

[Richard320]

It's a cartridge filter. I was hoping to swap it for the separator. Here's the view from the top. The current pool guy says we should cut off the stub and shove a hose down and see if water comes out somewhere. This is the best advice we've gotten.

I agree. Or maybe some compressed air or a leaf blower. Bubbles are easier to spot in the pool.

 

[Jtowne99]

What if we can't see where the air or water goes?

 

[Richard320]

What if we can't see where the air or water goes?

Then it might be the sewer. But I suspect your return side is split up into a couple zones.

 

[Jtowne99]

Is there a way to know for sure? Should we hire someone, like a pool builder or plumber, to come look? Like I said, no one seems to have an answer as to what is going on and we are lost as to what to do to fix this.

 

[Richard320]

Is there a way to know for sure? Should we hire someone, like a pool builder or plumber, to come look? Like I said, no one seems to have an answer as to what is going on and we are lost as to what to do to fix this.

Call a plumber. One: pool guys are swamped this time of year. Two: plumbers often have borescopes that can go down into pipes to see where they go and what shape they're in. Three: As far as plumbers go, cutting out some PVC with all that room will be laughably easy.

 

[Jtowne99]

Thanks. I'll call a plumber and see what happens.