Purex Filter With Unicel DE Grids..DE Keeps Coming Back Into The Pool..

by Claudia

I have a Purex filter with unicel FC1248 grids. All grids look good as new yet after the last filter cleaning we have DE in our pool - gets worst each day as pool runs. Is there too much DE in it? How much should it have in cups or dry weight?

Our pool man is stumped, but he does not have as much experience as the other man we had that moved away. HELP! DE settles to the bottom of pool. All grids have been cleaned and hand inspected. All just right!

Thank you. How much DE should go in our older purex stainless steel filter?

Thanks for your question Claudia

I'm not familiar with the FC series of Unicel DE filters. If you mean FG, then there is an FG Unicel replacement DE filter. I believe they run 24 inches. Normally when you get DE back into the pool through the returns it means there's a tear or hole in the grid. Your question said everything was fine, so we'll go from there.

DE filters can be a bit tricky to get in. When I started with my uncle's pool business in Arizona back in 1999, I watched him assemble and disassemble about 20 DE filters before I even attempted to help him. Getting the grids in without falling over takes time, patience, and experience. And that might be the issue.

Be sure the filter grids are lined up correctly.

Here's a good link to look at:

DE Pool Filter Maintenance

If your pool guy is using a coffee can, tell him to stop and use a proper DE scoop. If he says it's the same thing, I would fire him and get someone else who knows what to do. It's not the same thing. DE needs to measured just like flour. Use the coffee can to initially scoop the DE out, then gently pour the DE into the scoop; just like flour.

When people use coffee can they cram the DE in the can. You can't get the right measurement that way. Simply measure the sq. feet of the grids and use 1 pound of DE per 10 - 12 sq. ft.

Hope this helps and let me know how it turns our for you


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DE Filter - Particulates Floating In Water

by Ron

We have a salt water pool with a sta-rite DE filter. When we purchased the pool we were told that a DE filter was the most efficient filter you could purchase.

I am concerned that our filter is not working properly. When you swim in the pool you can see particulates floating in the water (even after we vacuum and run the filter for 16 hours a day).

When swimming at night, we also see particles floating ( really visible at night) in the water and what looks like a cloiud of particles coming out of the return jets. Is this normal?

In reading about DE filters, I wouldn't think you would see sediment floating in the water and coming out of the return jets.

Any suggestions would be appreciated.


Thanks for the question Ron

You're that in that a DE filter is the most efficient filter you can have, but they are the most troublesome. My preference is a cartridge filter. It rates better than a sand filter and not as much trouble as a DE filter. If you can somehow switch over to a cartridge, it would be a good investment in the long run.

It's not normal to have DE coming back into the pool. This is a huge problem that many DE filters have. 95% of the time the problem is a torn grid. If any are torn they'll need to be replaced. This is the #1 complaint from DE filter owners.

With the filter pump running, slowly add about 1 pound of DE for every 10-12 square feet of filter space. Basically it's this: 48sf. DE filter = about 4 pounds of DE. (check your owner's manual for details and exact specifications)

I strongly urge you to use a DE scoop. This will give you the best measurement. If you have a DE scoop then 1 scoop = 1/2 lb of DE. Make a slurry of DE in a bucket of pool water, then add to the skimmer. Don't use a coffee can or something similar.

DE Pool Filter Maintenance

Here are some posts to look over:

DE Leakage Into Pool - DE Powder Returning To Pool


Purex Filter With Unicel DE Grids..DE Keeps Coming Back Into The Pool..

The troubleshooting is pretty much all the same with most DE filters.

As you can see this is a common problem but with a little time and the right tips it should turn out right. Also be sure to make a slurry with DE and water BEFORE putting it in the skimmer. Get a 5 gallon bucket and a stir stick. Add the DE in and mix well, then put in the skimmer. This will help the coating of the grids.

The above links have the info. you need.

If you need immediate assistance (within 24 hrs) or for emergency personal assistance, you can make a donation of your choice and I'll answer your questions by phone.

Contact Me


Hope this helps and have a great Summer.


Comment By Ron
Date: May 26, 2012


Thanks for your reply. It is frustrating since we thought we made a good investment to pay more for a DE filter. Will take your suggestion regarding making a slurry in a bucket first then adding to the pool.

Also, if that does not help probably will end up changing the filter grids as well.


Comment By Robert
Date: May 26, 2012

I know it's frustrating. If you look on my Questions and Answers page you'll see the amount of questions concerning DE filters as opposed to cartridge filters. Those questions are the one's I posted. There were so many questions about DE going back into the pool that I had to combine some of them.

When I had my pool route in Arizona I really disliked installing and cleaning DE filters and changing out the sand in sand filters. But when a cartridge got dirty, I simply put a clean set in, cleaned the dirty cartridges, and set them aside.

Also, there's no backwashing with a cartridge so it saves about 200 gallons per month in water. With proper care the cartridges can last about 4 - 5 years.

DE filters can clean down to about 1 - 2 microns, cartridges about 5, and sand around 12 - 15. So while DE cleans literally a hair better, to me they're not worth the extra effort and headaches.

Good luck and let me know how it turns out.


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DE Filter Life With Tentacles

by Mike

I have a at least 15 year old Hayward DE filter that has the tenacles inside. A few days after I put in the DE it seems the sand from the DE comes back in the pool and rests on the bottom of the pool.

Do you know how long the filter canister should last? And are the "tentacles" replaceable or do I need a new cannister?

Thanks for the question Mike

My experience has shown that DE grids and/or fingers can last about 8 - 10 years with normal maintenance. 15 years is somewhat uncommon but you may have been one of the lucky ones.

There are so many variables as to why grids and fingers have long or short lives. Some are the pump motor is too big which can cause too high pressure for too long a period, over-loading the grids with DE, too long backwashing, not backwashing enough, constant green pool will will cause the grids/fingers to clog with algae.

If you've had the grids for that long, then all of a sudden you have DE going back into the pool, it's probably time to really inspect the fingers for any tears or rips. Do this first before going out and buying new fingers. If you find any rips you'll need to break down and buy new fingers.

What kind of valve do you have - a plunger style or a multiport valve? They too have o-rings that can go back. The multiport has a spider gasket that can crack and/or wear out. Here's a link of what it looks like:

Water Coming Out Backwash Hose During Filtration

If the valve doesn't "click" into place the gasket might be going bad or is already worn down.
Here's another post about that. It's for a sand filter but it uses the same multiport valve.

Multiport Valve Filter Setting Issue..Water Coming Out Of The Backwash Hose..

If you would like personal assistance, I do phone consultations for $35 per hour. It makes things go much faster and many people have found it extremely beneficial, saving them time and money in the long run. All your questions will be answered. I have nothing to sell you so you know I'm not bias. If you choose to not go that route, we can correspond by email but it will slow the process down.

If you've found this site helpful please consider making a donation. Thank you.

Hope this helps and have a great Summer.


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