DE powder on the surface of the pool
One of the more popular swimming pool filters is the diatomaceous earth (DE) filter but they can also be the most challenging especially when it starts blowing DE back into the swimming pool. DE filters filter down to the smallest micron value which means they are the best at keeping the pool the cleanest. That doesn’t mean that cartridge and sand filters don’t do a good job but DE filters have the ability to pick up for dirt and debris. That is why you will see this filter in areas with lots of vegetation and or trees/plant life. But what happens when you turn on the filtration equipment and you see the DE powder blowing back in the swimming pool? That is the subject we want to discuss in this blog post along with a few other hints to help you use this filter better.
First off, don’t jump the gun thinking something is wrong with the filter. It could be as simple as you put too much DE in the skimmer after you back washed. This is one of those cases where the exact amount of DE depending on the size filter you have is better than more. When you have more you might see an excess of DE blown back in the swimming pool. If you just back washed this could also be the reason. Now, if this is something that is occurring regularly or days after backwashing you might have the following:
- Torn filter grid – remember to check the entire grid
- Broken manifold
- Bad backwash valve
- Broken or missing air relief strainer
At this point, you will need to open up the filter and inspect the inside. Remember to check all the grids and the entire manifold for cracks. Even one small crack can make this happen. If you have a torn grid you will need to determine if you want to replace just the one or the entire set.
Tips on using a DE Filter
DE Filters are honestly pretty easy to use when you get the hang of it. The biggest things you need to remember is adding DE to the filter after you backwash. Remember to check the manual to help you with the settings on when to backwash. As soon as backwashing is complete, add the appropriate amount of DE to the skimmer so it will coat the filter grids. you might want to run the filter for at least 30 minutes.
Cleaning a DE Filter
Depending on how much you use your swimming pool you should at least clean your DE Filter once a year. This means opening it up and washing down the grids and inside of the filter. You will notice over time even with backwashing, DE will stick to the grids and manifold. You will need to remove this when you clean.
If you should have any other questions about DE blowing back in the swimming pool or have suggestings for future topics, please let us know!
over the winter I replaced grids that had small holes and replaced the top manifold that had a crack but still getting dirt blowing back into pool when vacuuming
I have DE returning in my pool with in 4 hours after i clean it. If i do not clean it it just keeps adding to the bottom of the pool.
I have installed new port and replaced the grids, plastic that holds the grids together and the air vent. along with the white pvc pipe and gasket it sits on. nothing left to change still have the same problem. did not even slow it down.
Now I tried putting in half the amount of the DE still comes back.
I DO NOT KNOW WHAT TO DO ANYMORE.
I have exact situation. However, have always used three diluted cups of de and never had an issue. I have replaced grids, manifold, O-Ring gasket on outlet elbow, the vent tube and the spider gasket on the valve head assembly.
Still the de blows back through the returns into the pool. Ialso did purchase a new air relief strainer and it is not flexible like the original one were. I believe they are for the new taller Hayward DE filter.
Any suggestions are welcomed.
I have cartridge DE I soak it over night and rinse it off that used to do it it seems the last 2 times De is not sticking to cartridge just blown back in the pool
A small amount of DE is going back into my pool only after bumping.
Approximately a half cup full. Why?
Is this normal?
Thank you.
Right after you change out the DE you will get a small amount but if it continues you should check the grids.
How often during the season should you backwash? Our pressure is always 10
Unfortunately, I wouldn’t always believe pressure gauges. They aren’t the most reliable. YOu can’t go wrong with backwashing once every month or so especially with the heavy swim load.
Could you please explain how a bad backwash valve can provide DE blow by? I have a pool that has 36″ sq ft grids which I recently changed in Jan ’20. I inspected the grids and manifold with no issues found. Thanks!
De coming into pool. Replaced de filter with brand new one and de still coming back into pool.Any ideas?
Do you have a cracked manifold? How much DE are you using?
I have the same problem, everything directly related to the filter, grids, manifold and O-ring are new, and the DE still going back to the poll, is it possible that something may be involved in the system that can the problem? could be slide back wash valve?
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Hi, great site.
I have a Hayward DE filter I bought 3 years ago. Previously I had a sand filter. After experiencing sand in my pool forever i thought I would give DE a try.
I have been experiencing the same problems you all discuss here. Every time my pump starts I get a shot of DE powder with fine air bubbles for about 10 seconds in my pool. I do not have any leaks around the filter tank clamp or any fitting on the tank. There is one leak at the thread fitting from the pump to the filter. It is only a drip.
Hi, I’m back with an update. I just disassembled the filter a checked the center plunger “O” Ring it was okay, however, when I loosened the several screws that held the rubber outer ring several screw were not very snug. There was also DE powder in the lip that seats in the mating clamping surfaces. When I reassembled the two halves with the rubber seal I used a 5/16″ nut driver on the screw head and a 3/8″ small open end wrench on the nut. Once the nut driver was snug I gave the 3/8″ wrench another 1/4 turn. I assembled the filter and bled air thru the tank vent and cycled the filter on and off about 5 times and the ammount of DE seem a lot less. I guess the inside of the fingers need to be rinsed out a few more time.
Wish me luck,
Take Care, hope this is helpful,
Joe
Thank you for the update. Good luck and keep us posted. Good job checking it all!!