I opened my pool this year after it having been closing it in August 2014. The water was green and filthy and after putting in chemical and running it since Wednesday it is blue but too cloudy to see the bottom. After backwashing and replacing the DE in my HAyward 2420 filter I noticed the DE going back into the pool. So far I have replaced three torn filter grids, as well as the multiport valve which was damaged. None of the O rings are missing or damaged, and I am not seeing bubbles in the filter. I let the filter run, backwashed when the pressure went up, but still had DE coming back into the pool when I went to replace it. I am at a loss as to what else could be the cause.
DE leaking back into pool despite repairs
- Thread starter ndesrochers
- Start date
- Jun 22, 2014
- 47,731
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Hello and welcome to TFP! 
Well, I can only think of a few things where DE would sneak-back to the pool:
- Damaged grid (which you replaced some already)
- Fingers/manifold damaged or separated at some point
- Too much DE added
Hummm, not sure if I missed anything. Perhaps another member will have a thought or two to assist if I missed something. Hope you get it resolved soon. Have a nice day.
Oh, and don't forget, please add your pool info to your signature by going to the top of the TFP web page (just under the Pool School button) and select "SETTINGS". On the next page look to the left for a menu bar that says, “MY SETTINGS” and go to "EDIT SIGNATURE" to enter your pool and equipment info there. Or you can click EDIT YOUR SIGNATURE. It will help us later. This link may also help you: Pool School - Read This BEFORE You Post.
Well, I can only think of a few things where DE would sneak-back to the pool:- Damaged grid (which you replaced some already)
- Fingers/manifold damaged or separated at some point
- Too much DE added
Hummm, not sure if I missed anything. Perhaps another member will have a thought or two to assist if I missed something. Hope you get it resolved soon. Have a nice day.
Oh, and don't forget, please add your pool info to your signature by going to the top of the TFP web page (just under the Pool School button) and select "SETTINGS". On the next page look to the left for a menu bar that says, “MY SETTINGS” and go to "EDIT SIGNATURE" to enter your pool and equipment info there. Or you can click EDIT YOUR SIGNATURE. It will help us later. This link may also help you: Pool School - Read This BEFORE You Post.
Now I have a couple of questions.
When you add de, does it shoot back out of the returns?
When you backwash the filter are you also putting the valve in rinse so you can clean out the bad water and prevent left over de in the multiport to go back into the pool?
Does de come out of the main drain when the pool is off over night?
When you cleaned your de grids make sure there are no holes anywhere. There is a plastic part that goes on top of the grids call the manifold, make sure that's not Cracked and there is a white tube on top the manifold with a sleave on it to releave taped air. If that's not there or the screen is gone you'll get blow back.
DE blow back is mostly caused by either or also
Holes in grids
Cracked manifold
Missing or damaged air relief on manifold
Bad multiport
Can I see a picture of your system it would help me thanks.
When you add de, does it shoot back out of the returns?
When you backwash the filter are you also putting the valve in rinse so you can clean out the bad water and prevent left over de in the multiport to go back into the pool?
Does de come out of the main drain when the pool is off over night?
When you cleaned your de grids make sure there are no holes anywhere. There is a plastic part that goes on top of the grids call the manifold, make sure that's not Cracked and there is a white tube on top the manifold with a sleave on it to releave taped air. If that's not there or the screen is gone you'll get blow back.
DE blow back is mostly caused by either or also
Holes in grids
Cracked manifold
Missing or damaged air relief on manifold
Bad multiport
Can I see a picture of your system it would help me thanks.