DE Filter Problems? Here’s How to Fix Them

Tired of DE cleanings that turn into all-day projects and callbacks? We dive straight into the realities of servicing DE filters on a busy pool route and share a field-tested system that saves time, protects your back, and stops fresh powder from blowing straight back into the pool. If you’ve ever rebuilt a vertical grid assembly on a hot driveway and questioned your life choices, this one’s for you.

We start with the essentials: how DE captures down to about 3 microns and why that pristine clarity comes with real trade-offs. Then we map the filter landscape—quad-style elements, the common vertical grid assemblies from Pentair, Hayward, and Jandy, and the legacy horizontal units that still pop up. You’ll learn the crucial part differences, like the capped grids for Pentair’s 2000/4000 series versus standard open-top grids, so you order right and rebuild once.

From there, we get tactical. You’ll get a faster, cleaner method to service vertical grids: remove the top manifold, clean and inspect each grid one by one, flush the tank sockets as you go, and avoid the time sink of a full teardown puzzle. We also pinpoint the exact causes of DE blowback—missing or stretched stem o-rings, cracked manifolds, damaged air bleeders, mis-seated clips, and tiny tears that act like highways for fresh powder. Small rips aren’t harmless; they’re a guarantee of white clouds at the returns.

When it’s time to replace, we offer a clear plan. If three grids are torn, replace all eight. When manifolds look brittle or bleeder parts are missing, a complete grid assembly often costs about the same as piece-by-piece parts and installs in minutes. 

• DE filtration advantages and messy trade-offs
• Quad vs vertical vs older horizontal designs
• Part differences between Pentair 2000/4000 and standard grids
• One-by-one grid cleaning workflow to prevent rebuild errors
• Risks of lifting the full wet assembly
• Causes of DE blowback and leak points to check
• When to replace torn grids and full sets
• Full grid assembly rebuilds for speed and reliability
• Three-

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Transcript

Why DE Filters Matter

Coaching Program Invitation

DE Basics And Micron Ratings

The Downsides Of DE In Practice

Types Of DE Filters Explained

Reassembly Pain Points And Fixes

Faster Cleaning Method Step By Step

Lifting The Full Assembly Risks

Why DE Blows Back Into Pool

SPEAKER_00 1:02

Hey, welcome to the Pool Game Podcast Show. In this episode, I'm going to go over some DE grid hacks for you, and I'll explain some things you can do with a D filter as far as knowing when to replace the grids, some tips on cleaning D filters, and just about everything about the internal work working of a D filter out there on your pool route. Are you a pool service pro looking to take your business to the next level? Join the pool guy coaching program. Get expert advice, business tips, exclusive content, and get direct support from me. I'm a 35-year veteran in the industry. Whether you're starting out or scaling up, I've got the tools to help you succeed. Learn more at swimmingpoollearning.com. And I realize the filters are area specific. We have a ton of them here in Southern California. These were the primary filters that were installed. A lot of us still have the old 2000 series Pentair filters out there. And D filters work with a basic concept that the grids are coated with diatomaceous earth. You can use alternate material like paralyte as well. And this material traps the algae, all of the kind of gunk that would go back into the pool, down to about 3 microns, which is the highest filtration of any filter out there attached to a pool. So it has higher filtration than a cartridge filter, which is about 10 to 20 microns, and a sand filter, which is anywhere from 20 to 40 microns. So the D filter does filter down to a much smaller micron. However, you'll come to see the diatomaceous earth or paralyte as a detriment on your pool route for a number of reasons. I think the main one is that it's a pain to clean them. You know, they're messy. If you clean them off in a planter, the diatomaceous earth kind of cakes up into a clay. You can clean them off in on a driveway. The powder is there for weeks sometimes on the deck. In the equipment area, the powder is there. You rinse it, then next week you rinse it some more. So it is kind of a messy thing to deal with. And then transporting it in your truck is messy as well. The bags rip, you have D spilled in your truck, you have to make room for several bags. Sometimes you're doing filter cleaning, and it's it becomes, in my opinion, a detriment to your pool service over time with the extra effort, adding the DE to the skimmer. And then you have, of course, the effects and the demoralizing effect of cleaning the filter, putting it back together, pouring a one pound of D into the skimmer, and having all that D shoot back out the return line into the pool. It's very frustrating. You almost want to you know jump in the pool at that point or you know run around in a circle and lose it because you have to take the filter apart and go through the whole process again. So I'll start just by saying there are primarily just three types of D filters out there. You have the quad D filter, which uses a more or less cartridge type style. It looks almost like a cartridge filter, but the cartridges for the quad D filter are a thicker material, almost like the same material coating the grids of the cartridge. Then you have the grid cartridge filter, and these are either vertical or horizontal. Now the horizontal filters are pretty much out of style. Stay right still makes one, but these used to be really popular in my day where you had the square grids and they were like just lined up together, you know, one after the other inside the filter. But now they're pretty much all going to be vertical and in a circle formation with the grids kind of overlapping each other, going around clockwise, basically. And this is the most common configuration of the Pinter Hayward and Jandy filters waterway. They all make these now with the vertical grids. And there are some benefits to this, and there are also a lot of drawbacks to this as well. The biggest drawback, in my opinion, is taking the filter apart and putting it back together correctly. And if you're new to the business and you've taken apart, let's say a Pinter FNS Plus filter, you take the lid off, you'll take the top manifold off, you'll take the grids off and clean them, and then you go to put it back together, and you're at a complete loss because it doesn't look logical. There's no clear way to put it back together. Then you go on YouTube and see one of my videos, and I show you how to do this by actually building it upside down. You put the top manifold on the ground, and then you put the grids around it upside down with the short partial grid in first, and then you build it around it, and then you put the bottom manifold on. Takes a little bit of time and practice, but you can do this pretty quickly over time. And then if you go to on my YouTube channel again and see the easy way to do this, you actually will be taking one grid out at a time and not taking all the grids out at the same time. And I'll go over that in a little bit in a moment on how to clean it properly and the best way to put it together. The other type of vertical grid filter is the Pentear 2000 and 4000 series, and it's sad that Penthare discontinued the 4000 series. I liked it because it was actually reverse with the top manifold on the bottom and the bottom manifold on the top, and it's really easy to clean and build these filters. So just be aware that there's a specific grid for the Pentare 400 and 2004 and 2000 filter. It's got a black cap on the end of it, and the grids for the all the other vertical filters, Jandy Hayward and Pentair, have just the white kind of clip on top that's hollow without the black end cap on it. So there are just two different types of grids basically, and most of the filters out there, you're going to use just the standard grids without the black cap on there. That's just made for the sometimes they're white as well, I should say, depending on which brand you buy. But they're capped for the 2000 and 4000 series, and for the standard filters, FNS Plus, Jandy, Hayward, it's just a white exposed top that has it looks like almost like it's got a clip to it that clips into the grid, which it does clip it, it clips into the top manifold, I should say, which it actually does do, and that's the main difference between those filter types. So just be aware of that when you're buying the grids that there are two different types. So let me go back to cleaning these things, and then I'll touch on changing the grids and inspecting them and things like that. Cleaning the these filters, the top manifold filters. In my opinion, it's much easier to take the top manifold off, clean that, inspect it, make sure there's no cracks to it. And then what I like to do is take one grid out, hose it off really good, and then I'll take the hose and I'll clean the area where the grid goes into the bottom of the filter to get all that DE out of that area. Of course, you have the backwash valve open right now, or you have the pump lid off so all that water can drain out the dirty water. So you're gonna be in backwash mode when you do this, and just make sure that you're hosing off the area in the filter tank, and then you put the grid back in clean. Then you take another grid out, clean that grid, inspect it for any cracks or tears in it, of course, and then you put that, then you hose off the area where the grid was at inside the filter tank at the bottom, put that grid back in. Repeat the cycle to you have all eight grids one by one cleaned back in the filter, with you cleaning the filter tank itself. Now, some DE is gonna go into the opening on the bottom. Not a big deal. You have a little bit of blowback in the pool sometimes, not a deal breaker because you just saved a tremendous amount of time. If you were to take all those grids out and try to rebuild it, believe me, it's gonna cause some brain damage if you haven't done it often enough. And the engineer behind it, you know, probably is no longer alive, so he's laughing in his grave, I guess. It's one of those things where it's a frustrating filter to rebuild unless you do it my method. Now, another method pool guys do, and I kind of recommend it, but I don't recommend it for a couple of reasons. One is that it can be really heavy and you can actually get hurt doing this. And two, it's not entirely effective when you want to inspect the grids and check for tears, but you can actually take you can actually pull the whole top, you can pull the whole assembly out connected together without taking it apart. Again, it's waterlogged, it's heavy, it's full of DE, and you may not have the strength to do this. And I don't recommend doing this because it's you could get a hernia basically, but if you are able to do it, and some people can do this, they take the whole grid assembly out with the top manifold, bottom manifold, the rods and the grids attached, take it to the grass area, and start hosing it off, turning it, spinning it, you know, moving it around so you get all the grids clean, and then dropping the whole thing back into the filter. That's kind of method too, and you have to be really strong. And sometimes it works best with like a 36 or 40 square square square foot DE filter, not the 60 square foot, and again it may be waterlogged and heavy, and you can't really inspect the grids thoroughly this way if you if you have it all connected together as one assembly. So I mentioned the frustration of pouring the DE into the skimmer and having it shoot back out the return lines. What are some things to look for? Some cracks and tear areas of the filter. The first thing, of course, is inspect the top manifold to make sure the air bleeder screen or the little thimble is intact. This could let D in also. The internal air bleeder usually has like a cloth cover, or again, it's like a little metal thimble type thing covering a tube in there. Either it's a thick tube or a thin tube. And if that's not there, D is gonna go back in through that area, so make sure that's covered. The next thing to check is something that's not quite as obvious, but it's the stem o-ring. So when you take the top manifold off, there's a pipe coming out of there, the stem pipe, and there's a little black o-ring that sits on there. Sometimes that's not even on there, and you just see the stem with like a little indentation. There's actually an o-ring that fits on there, but that stem o-ring tends to stretch over time and even tear. So you want to make sure you replace that stem o-ring. Each time you take off the top manifold to put back on the stem pipe, the e can get into the pool that way as well. Also, that's the without that o-ring in there. Sometimes the tap top manifold can actually lift up a little bit and let DE into the pool. So make sure that that o-ring is replaced and you have a new O-ring on there. Then, of course, you want to inspect the grids. Now, as the grids get older, the internal frame or skeleton starts to break down sometimes, and it could poke a hole through the grid. I've seen this happen many times where the internal frame is cracked, sometimes due to back pressure in the filter, and that causes holes to be poked into the grids. Sometimes you just have a tear at the seam at the top, sometimes you have a tear along the spine of the grid, and any tear in the grid will let DE in. Water will go to the area of least resistance, and so if there's a hole in the grid, it's gonna go right through back into the pool. And if you see any kind of tears in the grids, replace them. Even a small little tear, you know, two or three centimeters will let DE back into the pool. Believe me, a small little tear is kind of an optical illusion. So much DE goes into a small tear that it's hard to believe that that happens, but it does. A lot of times you'll take the filter apart and there'll be no DE in the pool, there'll be no evidence of an active leak because the DE tends to cake up like clay onto the grid. So this is something that you'll notice if you've been doing service long enough that you'll take the filter apart, you'll take a grid out, you'll hose it off, and you're gonna see like an a tear that's like an inch or two, or multiple tears in the grid. Sometimes debris is stuck in there, but there's no evidence of DE in the pool or spa at all because the D is kicked on there so well, it's almost like covering that hole up with a patch. But when you clean it, at that point you've removed the patch, so to speak. And if you put it back together with that tear there, DE's the fresh DE powder will go right back into the pool. So remember, when you're recharging the DE filter, it's fresh powder that's not kind of clay-like yet. And so that fresh powder will definitely find any kind of hole and go back into the pool. And that's why this phenomenon exists where you'll clean a filter with multiple tears in the grids, but you'll see no DE in the pool and you'll see no ill effects of having those tears in the grids until after you clean it and put fresh DE in. So it's really important that you replace every single filter grid that has a small tear in it because the fresh powder will go right through back into the pool. My rule of thumb is that if there's three grids with tears in it, I replace all eight grids at that point because chances are you'll put it back together, you'll replace three grids, let's say, put it back together, and then two or three weeks later you're gonna see DE in the pool because a grid, one of those five remaining grids, tore, and it's something that you have to kind of mentally visualize happening. Because if three grids are torn, that means that the other grids are definitely compromised or weaker at that point. Plus, it makes it easier to manage the filter when you change all the grids at the same time, versus two grids here, two grids there. So if there's three or more three grids with tears in it, I replace all eight grids at that point. If you take the filter apart and the top manifold looks pretty old, like it's gonna crack. Sometimes you'll see like little hairline cracks in it, but there's no actual cracks there, and it looks kind of brittle. It's really old, maybe 10 years old or so. I would recommend getting a complete grid assembly at that point when you're replacing the uh cartridge, the cartridges, the grids in the filter, and they sell all these grid assemblies for all the different filters. For example, if you have a Penthair FNS Plus 60 and you want to get the grid assembly, and they're somewhere around$350,$300 or$400 or so, maybe less than that, depending on your supplier. And it's sometimes almost the same cost or cheaper than buying a top manifold, bottom manifold, the stainless steel rod or rods, and then all eight grids. And the nice thing about it is that it's a really quick job where you take out the old top manifold, all eight grids, and the bottom manifold, and the rods, and sometimes it pays to take it out all as one piece if you can, and then you clean out the interior of the filter tank, and then you drop the grid assembly into the tank, and basically you just replace a stem o-ring, and you're ready to go with a brand new top manifold, bottom manifold, stainless steel rods, and the new grids. And you can find these just by typing, you know, Pentair Grid Assembly FNS plus 48. The FNS plus 60 is actually the part number is 590 23300, and you can you can get these for every filter on the market basically, almost, and this will be a complete new rebuild of the interior part of the filter with really no problems. So I covered kind of where the you can see obvious tears and cracks in the top, and there's really not much more area where the D can get back into the pool except the stem o ring, crack in the top manifold. If you have a 4000 series penter filter, the bottom manifold can get a crack as well, and a normal an obvious tear in the grid, and then one other area that you may want to pay particular attention to is where the grids go into the top manifold. Sometimes those little clips break and you don't notice it that they're actually snapped because they have to set into the top manifold perfectly to seal. And the top manifold has to cover that white clip completely. And the way to visualize it is the top manifold should sit on the grids where all you see is the grid material with no exposed white part, and you can't if you see through that area where it clips into the top manifold, D you can get in there as well. You don't want to over-tighten it to the point where you're breaking the white clips off that go into the top manifold, but you do want it on there snug enough so that you have the black top manifold, and then all you do, all you see is the grid material without seeing that white clip going up in there, and that's really important because that's another leak point that I see a lot. When I take apart a filter, I'll see that the top manifold was not on tight enough and the E was going in through that area. So just pay careful attention when you reassemble it. But I do highly recommend getting the Pentair grid assembly if you're going to replace all eight grids at that time, and the top manifold looks older. Maybe the air bleeder is missing and there's like a twig stuck in there, and maybe there's nothing capping it at all, or the the air bleeder cover looks really worn out. Definitely get the assembly, grid assembly, and replace all of those. How to know when to replace all the grids. Every three years is a good point to replace all eight grids, even if there's no tears in them. It's a good preventative way of making sure that you're not having the problem of adding DE and then having to take it apart again because there's a tear somewhere or problem. So every three years replace all eight grids without argument and put new grids in. And I can guarantee you you'll have less torn grids over time and less frustration if you stick with that three-year timetable. Because by the time it gets to year four, even year five, if you can get that far, the grids have deteriorated, the frames are cracked inside. You may notice that they're stained and they're not quite as effective. You know, they're not white anymore, they're just kind of a yellow-brown color. That's when you want to replace the grid. So every three years would be my recommendation. And then whenever you see the top manifold kind of looking like it's cracking, do the complete grid assembly on that at that time. It saves you time and money and effort later, and it's really easy to do. So D filters are definitely manageable, and you know, and when you can, of course, always when they want to upgrade the filter, go with the cartridge filter, in my opinion. It's much easier to clean and maintain. You have much more square footage, and you have less headache with worrying about tears in the grid, cracks in the manifold, D getting in the pool. It's a much cleaner filter type, and it's something that I always convert people to when I get the chance to do that. If you're looking for other podcasts, you can find those on my website, swingpoollearning.com. Just click on the podcast icon there. That'll take you to a drop down menu with over 1800 podcasts. And if you're interested in the coaching program, you can learn more at PoolGoaching.com. Thanks for listening to this podcast. Have a great rest of your week. God bless.