possible DE leak and small air bubbles from return line

[andrewdaddy]

Hi,

My pool was perfect before I left for vacation on 7/30. I had my neighbor pour bleach daily into the pool and clean out the skimmer. When I came back, I decided to backwash the filter since it has been over a month since I had done so. I believe I might have a small DE leak coming back through the return line. At the beginning of the season in May, I replaced all the grids with new ones and my pool was crystal clear with no signs of DE coming back through the return line. Once I came back from vacation when I tried to backwash, I poured DE into the skimmer and found out after the fact that there was no suction and the DE spilled into my pool. I opened up the basket with handle from the pot connected to the pump and found a large amount of pine needles and DE media which I cleaned out thoroughly. I've also vacuumed the pool twice to remove the DE. Now, I also notice small air bubbles coming out of the return line which I didn't notice before. I'll check the pool again tomorrow to see if there is any DE settling on the bottom. If I do find more DE there, do I need to open up the filter like I did at the beginning of the season to find a possible hole in the grid? This is so frustrating since I had this problem previously but it went away when I replaced all the grids. Is it possible for debris to pass through the pump into the filter and cause holes in the grids? I have been using the BBB method. Thank you for your help!

Kayak Above Ground 5000 gallon pool
Leslie's Crystal Clear II DE 24 square foot filter
Pentair Dynamo 1 horsepower pump

 

[Texas Splash]

Just seeing your post from a couple days ago, but if everything was looking good before you left and you returned to that situation of overloaded pine needles and such, I would probably go ahead and inspect that filer inside really well. If you pump strainer basket was that full, no telling how many more needles made it past the basket into the filter media itself. Hopefully and easy fix for you and nothing more than just some of your own time.

 

[andrewdaddy]

So the pool looked good yesterday but after running the pump for 3 hours, there is some more DE in the bottom of the pool. Also the water is not as clear as it was before my vacation and the chemistry is fine. So now, I believe there is definitely a small leak in one or more of the grids. I know it can be challenging to find small holes in the filter grids. Should I just bite the bullet and replace all the grids? Is there a good way to figure out where the hole might be?

This season I started using a skimmer sock which made the skimmer more buoyant and subject to inverting when the pump is off and waves are created by kids splashing and then not doing its job and letting the pine needles pass through. Now I put a rock to give the skimmer some weight so this doesn't happen again. But this still doesn't fix the problem of DE leakage.

 

[andrewdaddy]

I replaced the 8 DE filter grids and I still have a problem with a slow DE leak. When the pump is running, I do not see any DE powder coming into pool but it clearly settles on the bottom of the pool after it runs for several hours. What is my next step to troubleshoot the problem? I replaced the multiport gasket last year. I have the 3 port valve set for 50/50 top skimmer and bottom drain. Are there any washers that I should replace? When I have the 3 port valve set for 100% top skimmer, I see tiny air bubbles coming out the return line. When I have it set for 50/50, I don't see any bubbles. And is it not safe to swim with some DE powder on the bottom of the pool? Thank you! This is so frustrating!

Kayak Above Ground 5000 gallon pool
Leslie's Crystal Clear II DE 24 square foot filter
Pentair Dynamo 1 horsepower pump
Hayward SP0710XR50 Pro-Series Vari-Flo Backwash Valve Coupling

 

[Texas Splash]

A little DE on the bottom of the pool won't prevent you from swimming, but it is something that needs to be resolved. The air bubbles that seem to be visible from the 50/50 setting shouldn't have any bearing on the DE issue, only that somehow a little air is getting into the system on the suction side. Things to come to mind for me are:
- All new grids; any chance the manifold or other internal connections had a defect?
- Any chance of over-charging the system with too much DE?
- Multiport gasket only a year old; perhaps it got kinked or distorted by turning the opposite way from normal operation?
- The extra DE that's been in the water and settles, do you vacuum to filter or waste?
- Have you tried (if you can) attaching a nylon or something similar to a return jet(s) and experiment with different settings on the multiport to see if you can pinpoint if the DE is returning to the pool during filter, or if it happens at any other settings? That might tell you something about your spider gasket.

Maybe this or some other replies will help give you a good path forward to finding that pesky problem. Keep us posted, and have a good day.

 

[andrewdaddy]

What confuses me is that before I left on vacation, I did not have an issue with DE leaking and the only thing different was a ton of pine needles in the pump pot and some more in the filter itself. I'm pretty sure I didn't overcharge the system. I only used 4 cups instead of the full 5. And I haven't turned the multiport the opposite direction this season at all. I guess I could open the multiport to inspect the spider gasket. I haven't tried attaching a nylon, but I can try that. I vacuum to filter and I don't see any DE coming back through the return line at first but after a couple hours, I see the DE settling.

Thank you for your thoughts!

 

[andrewdaddy]

So I did nothing except for leave the 3 way ball valve in the 50/50 top skimmer / bottom drain position and there is less DE in the pool now. I wonder if there is some retrograde flow through the bottom drain if the ball valve is in the 100% top skimmer position. Let's see what happens the next couple days. It's almost the end of the season so maybe I can punt this until next year!