DE Matter Returning Back To Swimming Pool Water

by James Nightengale
(Virginia Beach, Virginia)

I recently replaced the DE sand in my swimming pool filter and it seems that a large amount of the sand filter media has ejected back into the pool through the jet valves.

Is this a serious problem?

Thanks for your question James

I believe what you're talking about is a normal swimming pool sand filter. I'm not quite sure why you're referring to it as a DE sand filter but if you're mixing DE (Diatomaceous Earth) with your pool sand, you might be getting the wrong information.

Swimming Pool Sand Filters..Inground Maintenance..Above Ground..Care

Swimming Pool DE Pool Filters..Care..Maintenance

You never want to mix the two together.

When you empty your sand filter be sure to check the laterals and diffusers, if the filters are equipped with them. Many times a broken lateral or tube is the cause of sand going back into the pool.

If the laterals are fine and you've just put new sand in the filter, then you will expect some residual sand, dirt, and debris to come back out through the returns. This is normal and should not be a concern.

Check your owner's manual on the amount of sand to put in the filter. The manual should also tell you how many inches of sand is needed so keep an eye out for that as well.

The sand that's returning back into the pool should lessen over time as the pool filter media has a chance to settle in the sand filter.

Swimming Pool Sand Filter Problems..Troubleshooting..Maintenance..

Allow your swimming pool sand filter to do its job and have enough pressure to filter properly.

If after a week or two and maybe a couple of bachwashes you still are having this it obviously is something within the sand filter.

Thanks again

All the best


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Several Tears In The Filter Panels Of My DE Filter..Loss Of Suction..

by Felipe
(Austin, TX)

I found several tears in the filter panels of my DE filter. I've replaced all 8 panels but now after an hour or two of operation, the pressure climbs up to 30-35 pounds of pressure and I loose most of the suction.

I know I'm not overloading the unit with powder.(4 lb. for a 35 sq ft filter).

Any ideas as to what's wrong?

Thanks for the question Felipe

I know from personal experience that DE pool filters are the best at cleaning the water, but they can be the most troublesome. This is what I've found while maintaining DE pools in Arizona. I will assume because your grids are new that there are no tears or rips.

First thing is to check the gauge to make sure it still works. Turn off the system and if the gauge still reads 30 - 40psi, replace it with a new one.

Next, be sure the grids are placed correctly, not backwards. If you get DE on the wrong side of the grids, it will cause a high pressure.

Also, and I'm sure you are but some people don't use them, use an actual DE scoop, not a coffee can. A DE scoop will give you the most accurate reading on the DE powder. I always measured DE the same way I measure flour. Get a coffee can and scoop DE into it, then take the DE in the can and gently pour it into the DE scoop. This will give you the most accurate measurement for the DE powder. It's a little more time consuming but it's worth it.

I never had an issue when doing this. Some people might "jam and pack" the DE into the can or scoop which is not the right method. You're using too much DE when you do this and over time it will clog up the grids.

Here are some sites that I still use when I need some info. You're never too old to learn new things:

And this page from my site:

Assembly Of Vertical DE Filter Grids - What A Pain!

Hope this helps and good luck with your filter


Average Rating

Nov 16, 2010
DE Filter Pressure Down To 18 - 20psi... NEW
By: Felipe

Man, what a wealth of information. Thank you very much. However, I wonder how the grids could bhave been installed backwards.

Do you mean that maybe I have them in the wrong order?

This afternoon, I backwashed the filter for a couple of seconds and got the pressure down to 18 PSI. I added a coffee can of de powder and the pressure seems to be holding between 18 to 20 PSI.

Again, thanks for your help.

Thanks for the follow up. Always glad to help.

Good luck with the filter and if you have any pics. you'd like to send I'd like to see them. I'm also running a swimming pool article writing contest and the winner will receive a new Taylor DPD K-2006 pool test kit, the best one on the market.


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How To Clean The DE Filter Grids With Oil & Residue

by John C. Burian
(Bentonville, AR)

This is my 33rd year of maintaining a pool in two different homes, both with a DE filter. My present pool is 34K gallons, and I do not backwash the filter, in fact I've had the BW tank removed.

When it's time to clean, I do it the hard way by disassembling and cleaning. Now, for the first time in all the years, the DE is not sticking to the grids, but falls to the bottom of the tank when shut down for the night. I suspect that the grids need to be cleaned.

I've read somewhere that you should soak them in diluted acid. That's fine, BUT I'd need a huge container to do that and then how do I dispose of all that acid?

I need an alternative method to clean them.

Can you help?

Thanks for your question John

My first question would be do you know why you're getting grease and gunk in your filter after all these years of not having it? Be sure to take a good soapy shower before and after going in the pool. No lotions of any kind should be allowed in your pool.

You are correct in saying that cleaning your swimming pool DE filters with muriatic acid is one way to get the filter clean.

First I would encourage you to get, if you don't already have one, a DE cleaning wand. This makes the job a little easier and can be found at most pool supply stores.

Muriatic acid is one of the most caustic acids around so you always need to be careful when using it.

When I degrease the sand filters at the Y, I use a product called "Filter Fresh". This product is a bit less caustic than regular muriatic acid and does a great job in getting the grease out of the sand filters. After I let the degreaser sit overnight, I simply start the system in "BACKWASH" mode and it goes out into the sewage system.

You may want to look into this product as it does a wonderful job for me. I'm not sure what it might do to plants or grass so you may want to clean them in a gravel area or in the street.

There are products for cleaning grease from DE filters. It's called, simply, DE Filter Cleaner. You can attach the sprayer and evenly coat the elements, then rinse clean. A local pool supply store should have it on hand.

I would try these products first before using muriatic acid.

Hope this help and have a great Summer


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We Are Getting Chunks Of DE In Filter Basket...

by Tom

We have a 10,000 gallon heated indoor pool and have new DE filters in place. Each day we are having to backwash and replace DE. When we backwash we are getting chunks of what we thing are hardened DE but are not sure.

Additionally our heater and circulation pump are shutting off because of high pressure readings in the filter.

Could this be caused by clogs?

Thank you in advance for your assistance.


Thanks for your question Tom

DE swimming pool filters are the very best at filtering your pool water...but they are the most time consuming. When they're backwashed, you never can know how much DE is actually being backwashed out, and therefore, you really can't be sure if you're putting in the correct amount of DE.

I would advise you to clean the grids from top to bottom. Inspect the DE grids for rips or tears. If they're more than 20% worn, ripped, or torn, they'll need to be replaced.

You can go to these links for more information:

Swimming Pool DE Pool Filters..Maintenance..Pressure..Backwash

DE Pool Filter Maintenance..Problems..

Also, check the pool pump, basket, and impeller to be sure that there are no chunks of DE in the system that can clog up the pump motor.

Be sure the pump motor is off and the breaker switch to the motor before doing anything.

Your high pressure issue might be related to lack of flow through the DE filter. If the filter is too clogged with DE, then that would restrict the water flow and cause the pressure to rise.

Be sure you're using a DE scoop, not a coffee can or something similar. You want to get as close as possible to the right amount of DE.

Hope this helps and have a great Summer


Donation..My Pool Guy..

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Why Does DE Material Stays At The Top Of Filter And Grids?

by John Blausey
(Rohnert Park, CA)

Just bought a home with a 35,000 gallon pool.

DE filter was full of algae as was pool. Back wash did nothing as water always ran clear.

Removed grids and cleaned.

Grids look fine. No rips and cleaned up well. Re-installed and re-charged with DE.

Had a leak so I removed the filter lid to clean and install gasket. I noticed all the DE was on top of the assembly and only coated the top 1/3 or so of the grids. The pressure while running was 8 to maybe 10 PSI. It's never been higher even before cleaning.

I suspect my valve needs to be rebuilt. It's a 2 position slide valve.

Also I am wondering if there is a clog or broken impeller that is causing the low pressure.

Would low pressure cause the un-even coating on the grids?

Thanks for the question John

I get more questions about DE filters than any other pool filter. They're the best in keeping your pool clean, but they are the most troublesome.

A problem could come from not having the proper flow of water through the system. A clogged impeller could be the reason.

Turn off the system, remove the pump basket, and check the impeller. If it doesn't turn freely, you may have a problem.

Most of the time residential pools run anywhere between 20 - 60psi, depending on the horse power of the motor. Most of the time a 1/2 HP pool motor is fine.

Be sure you're using a real DE scoop, not a coffee can. You'll get the most accurate measurement with a DE scoop. Scoop out the DE with the coffee can and pour that into the DE scoop until its level. Just like measuring flour.

Always premix the DE with water in a large bucket, maybe a 5 gallon bucket, to get a nice slurry, then pour that into the skimmer. It otherwise might clump up in the filter rather than properly coat the filter grids.

Sometimes the problem with not doing a premix is that the DE might not spread evenly inside the filter. You'll get big clumps and bare spots on the grids, usually near the middle or corners, and a thin cover in other areas.

You can also check the nibs (if equipped) on the manifold, top and bottom, to make sure they are not broken or cracking. The nibs are on the manifold that hold the grids in place.

DE Pool Filters

DE Pool Filter Maintenance

Hope this helps and let me know how this turn out for you. Others have the same problems.

Have a great swimming season and please remember to sign up for my free monthly E-Zine newsletter.


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