Guts of QuadDE Filter

[JoyfulNoise]

I thought it might be useful to start a thread for all of us Pentair QuadDE filter owners to share some "best practices" when its comes to cleaning out a QuadDE filter. Jblizzle has a great sticky thread on how to clean a standard grid type DE filter. This isn't meant to replace anything he has written but to add some pictures and highlight some differences between a grid style and a cartridge style DE filter. Since my filter was due for its annual deep clean, I thought I show some pictures of the process. What's listed below is what I do for cleaning the filter, others may have different tricks and tips to share...if so, please do respond!!

How To Start

The first step is to always gather the tools you need for the job. This is what I need based on my filter and the location that it's in. Your list may vary.

7/8" deep pocket socket wrench (I use a 1/2" ratchet handle)
Large flat-head screwdriver
Rubber, wooden or plastic mallet (mine is a plastic mallet used for tent spikes)
Water-proof Silicone lube (I do NOT use teflon based or teflon-added lubes)
WD-40 White Lithium spray grease (only used on the saddle clamp nut & bolt, never anywhere inside the filter)
Large plastic tarp (I use this to direct the flow of water and waste from the drain hole as water causes a lot of erosion around my equipment pad)
Lots of rags (I find old dishcloths work the best)
Garden hose with good pressure!!
Bar-Keepers Friend liquid cleanser (more about this later)

Process:

1.Since my filter always has water in it (a check valve keeps it from draining), I always start by backwashing the filter. This gets rid of a good portion of the DE from inside the filter and makes cleaning out the filter body a little easier.

2. After backwash, I cut the power to all pumps. I leave the backwash valve in backwash position and open the high flow bypass valve (HFB). This will cause all of the water in the filter above the level of the output coupling to drain out through the backwash line. This way, most of the water in the filter flows out of the backwash line and leaves only a small amount in the bottom of the filter.

3. After the filter drains, I remove the saddle clamp by undoing the tension bolt assembly (7/8" socket wrench required). I sometimes spray some of the lithium grease on the threads to help the bolt move smoothly.

4. With the saddle clamp removed, I lift off the top lid and put it aside (this is heavy and, if you can't lift more than 50lbs, you should get help). Once the lid is removed, this is what I find -

5. I then open up the drain plug on the bottom of the filter and let the remaining water (and some spent DE) drain out. I lay out the tarp so that the flow from the drain plug is directed down the rip-rap embankment so as to not cause soil erosion (my equipment pad is in a lousy location some day I will need to build a very big and very expensive block retaining wall and buy A LOT of fill sand to replace what erodes away). Another trick I have used is to get some 1-1/2" DWV pipe and fittings with a 90-deg elbow - there just enough room to shove the pipe fitting and pipe under the filter and capture most of the water...it's not great, but it works.

6. With my garden hose, I rinse as much of the muck off of the cartridges as possible allowing all the muck and spent DE to drain down the tarp. I remove each cartridge one at a time and continue to rinse out the filter body.

7. Pentair uses an internal, stainless steel ring inside the filter body to aide in the saddle clamp having a stronger circumference to seal against. You can see a small amount of corrosion-

I use the BKF cleanser and a soft sponge to clean away the rust stains. Why BKF you ask? Because it's just silica grit polishing compound with oxalic acid in it. The oxalic acid is very good at chelating and removing rust stains. This will all be rinsed away as I continue to clean and remove cartridges.

8. At this point, the filter body and bottom flange assemble are clean -

I'd like to take this time to point out that Mark (mas985) was right about the fact that the input of water into the filter under normal operation is actually diverted downwards and towards the lower wall of the filter body to create lots of turbulence so that any DE that settles at the bottom is easily stirred up. The Pentair Owner's manual does not show it that way (it shows it pointing upwards) so it's nice to see that they designed the filter input with turbulence in mind.

9. Now the "fun" part, cleaning off the cartridges At this point, I go to the back wall of my property with my garden hose and a bucket or pail turned upside down so that the filter can be held upright on it at a level that means I don't have to bend too much. Cleaning takes A LONG TIME as the DE is all entrained on the filter cartridge surface with every form of organic and biological nastiness. It's basically a goopy muck of human bather waste, leaf litter, hair, bugs, decomposing and oxidized organic compounds forming a zombie-like flesh on the cartridge surface.

Pro-tip #1: Wear long pants, and a long sleeve shirt, preferably clothes you don't like too much...and then be sure to WASH THEM right away after you are done....

Pro-tip #2: KEEP YOUR MOUTH CLOSED! (don't ask how I know that )

One down, three to go -

Almost there.....

Now those are some nice-looking cartridges -

Just a note on removing and replacing the cartridges -

>>The top black flange fits snuggly into the holes in the top of the cartridges. Sometimes it helps to take a large, flat head screwdriver and VERY VERY VERY GENTLY pry it up a little bit....did I mention being GENTLE!!! Also, in the middle of the top flange assembly is the spring that the cover pushes down on and the air-bleed tube with the metal mesh top cover. If the mesh looks bent and flattened down, that is TOTALLY NORMAL. The mesh gets coated with DE and is only there to be an air bleed for the filter to keep large air pockets from forming in the top of the filter. Be careful with all of those parts, clean and replace them.

>>When putting the black top flange back on, I find that I need to use my mallet to VERY, VERY, VERY GENTLY tap the flange back onto the cartridges so that they seal up nicely....did I mention being GENTLE??

10. Clean up the filter body o-ring using water and rags. Re-apply a necessary amount of silicone lube (all that is needed is a thin layer) and re-install the o-ring.

11. Remove the High-Flow Bypass from the top of the filter body by unscrewing it (careful, there is a rubber grommet there to act as a seal). The HFB valve looks like this -

12. Disassemble the valve by making sure it is the open position and then GENTLY push on the two side tabs to split it apart. Some force may be required -

13. Clean the valve body and twist flange. Those two o-rings are standard sizes that can be found at any hardware store (I get replacements at Ace Hardware). They can get coated with DE and worn down over time. I usually have to replace them every two years or so. I remove them, clean them off and then re-lube them. It makes opening and closing the HFB valve easier.

14. Clean out the top body assembly of the filter, replace the HFB valve and reassemble the filter. Be sure that the drain pug has been replaced (hand tight is fine).

15. The saddle clamp bolt and screw should be cleaned off with a rag and I like to lube the bolt and screw with white lithium grease. None of that should ever be sprayed directly into the filter body. The saddle clamp bolt should be tightened down with your ratchet until the anti-backlash spring is fully compressed (no gaps between the turns of the spring.

16. Put the backwash valve into the filter position (normal operating position), open the high flow bypass valve and start up the pump. At this point you should hear lots of air hissing out of the HFB valve. Keep running the pump until all the air is out of the filter and water is flowing ("gushing like a fire hose" is a better description) out of the HFB valve. Close the HFB valve, let the filter pump run. Note the clean, uncoated filter pressure.

17. Follow you standard recharge procedure for the DE filter. I only recharge my filter with 10lbs of DE at startup. When I do backwashing (which is only at most 3 times per year), I only use 4 lbs of DE to recharge after a backwash and not the full 10lbs again. Using that much DE is overkill as backwashing typically only removes about 50% of the DE at best. Please follow whatever is your normal procedure.

Hope this helps and please respond with any additional tricks YOU have learned over the years.

 

[jblizzle]

Nice addition! I will add a link from my article to this when I get to a computer.

EDIT: I have added various hyperlinks between the various DE filter threads.

 

[Texas Splash]

Great post Matt. Question - On step #4, after removing the saddle clamp, does your lid ever get stuck to the point that simple lifting or rocking doesn't break the seal? Have you ever had to simply turn the pump on "quickly" simply to pressurize the filter with water to help lift the lid and break that seal? Ideally I suppose a good silicone application from the previous maintenance would help prevent that, but I was curious if it ever happened to you.

Step #8 ... all clean. Brought tears of joy to my eyes. Showroom nice.

 

[JamesW]

The Quad DE filter has a design where the lid is not likely to get stuck. In any case, one should never pressurize a filter to get a stuck lid off. The lid can come off quite violently if under certain conditions, like having air in the filter.

Someone could get seriously injured if they got hit by a lid coming off under pressure.

 

[Texas Splash]

Design prevention - check. I wasn't aware - good to know. Safety - certainly James (priority #1). I'd never want to imply anything otherwise. But I was curious about other's experiences as I've seen it done by some pool owners (again "very" quickly). I expect this thread will be used by many newbies, some who may experience a stubborn filter housing that wasn't as well maintained as Matt's or perhaps previous owners of their pool. If the design of this housing prevents that from ever happening, it becomes a non-issue which is perfect. Thanks for the info.

 

[JoyfulNoise]

The Quad DE filter has a design where the lid is not likely to get stuck. In any case, one should never pressurize a filter to get a stuck lid off. The lid can come off quite violently if under certain conditions, like having air in the filter.

Someone could get seriously injured if they got hit by a lid coming off under pressure.

Agreed. Never been stuck. Proper lube and opening of the HFB valve is key.

I saw that YouTube vid of that guy popping the filter off and thought it was both unnecessary and very dangerous. Not something anyone should ever do.

With that said, Pentair could do folks a solid by redesigning their lid with integrated handles or handle like cutouts molded into the lid body. It is an unwieldy design as-is.

 

[gary300]

Very nice write up and pictures. I have a Quad 60 so your info is very pertinent to me. I would like to add a couple of steps if I might.

1. I clean the groves in the filter body and the top that the big O-ring seats into thoroughly so that the O-ring does not sit on any dirt or debris.

2. As I tighten the the large clamp, I tap it several times with a rubber mallet all the way around the perimeter to help seat the O-ring properly in the groves.

 

[bdavis466]

I thought it a little odd when you mentioned the 90 inlet pointed upward as I didn't recall it that way in mine... Good to know I'm not crazy.

Why do you bother back washing? I tear mine apart yearly but the pressure never rises enough to warrant it.

 

[JoyfulNoise]

Very nice write up and pictures. I have a Quad 60 so your info is very pertinent to me. I would like to add a couple of steps if I might.

1. I clean the groves in the filter body and the top that the big O-ring seats into thoroughly so that the O-ring does not sit on any dirt or debris.

2. As I tighten the the large clamp, I tap it several times with a rubber mallet all the way around the perimeter to help seat the O-ring properly in the groves.

Thanks! I actually do both of those but forgot to mention the "mallet tapping" trick. It definitely helps when trying to reseat and tighten down the saddle clamp. I was also going to joke that Pentair design engineers just assume the user of these filters are humans with four arms and three legs based on their expectation of how someone can reasonably handle some of these parts

I thought it a little odd when you mentioned the 90 inlet pointed upward as I didn't recall it that way in mine... Good to know I'm not crazy.

Why do you bother back washing? I tear mine apart yearly but the pressure never rises enough to warrant it.

Ya know, I may switch to a bi-annual tear down instead of backwashing (maybe April & October). It would save me on DE too (20lbs total instead of 22lbs). It has been the case that, during the swim season, I have noticed a slow down in the flow and the backwash corrects thats. It's funny because I too see very little change in pressure except over many months (6 months or more). What tips me off that I could backwash is that the flow changes. The suction side vacuum starts to run a little slower and won't climb the walls (not that that is important to me) and the flow from the spa spillway looks slower. I usually see those two things well before the pressure changes. I suppose if I had one of those high quality pressure gauges and/or flow-vis flowmeters on the system, I would probably be able to measure the effect better. But I don't so I go with the visual cues.

But yes, backwashing is annoying and, in my case, actually a slight problem. As I mentioned, my equipment location is far from optimal. It's on the side of the casita and it's up high on a rip-rap embankment. Over time water flows down the embankment and it erodes a little bit. Sometime in the next few years I'm going to have to build a very long and very expensive cement block retaining wall and pay for a lot of labor to backfill the wall with replacement sand from all of the loss. Either that or my equipment pad will eventually fall off the side of the casita....

 

[JoyfulNoise]

UPDATE - When Good Valves Go BAD [queue the theme song to the TV show COPS]

SO I thought I would post this update to describe a problem that can occur with a filter and what happens at the pool side. Here's a picture of my current High-Flow Manual Relief valve -

The arrows show a water leak in two spots - one at the threads of the pressure gauge and another under the twist handle. The leak is tiny (a very, very slow trickle) so my pool is still running at this point since I don't want to lose filtration and chlorination. A new valve is on order and will arrive today (gotta love Amazon Prime same-day delivery ). Once the new valve shows up, the fix should be an easy swap [pool owner furiously knocking on wood]. This can be a common problem for these types of valves - as they age, the plastic gets brittle and the constant thermal expansion difference between metal and plastic stresses the plastic threaded fitting causing it to crack and leak.

But, are there any signs of this issue at the pool? Why yes, there is. Because this is a DE filter, the DE can show up as being blown out of the pool returns. Why? Because a tiny leak like that allows air to enter the top of the filter and, when the pump is off, the water level of the filter will very slowly leak down below the internal air bleed assembly. Once the pump turns on again, water rushes into the filters air space and churns up all of the DE. Some of this churned DE will blow out through the internal air bleed assembly. The result is a large cloud of DE shooting out of the returns (and a very unhappy pool owner seeing his crystal clear pool go cloudy ).

Another tell tale sign is that there can be a large volume of air in the filter that will blow out through the returns. Normally, when my pump turns on, I see almost no air come out as the water level in the filter never changes. But, with an air leak into the filter, the large volume of air at the top gets relieved and blows out through the returns. This is not normal and so is another tell-tale sign of an air-leak at the filter.

Hopefully this will help others in the future.

Matt

 

[Ocgasman]

First, I want to thank Matt for a really outstanding and thorough explanation of cleaning out the Pentair Quad DE! It was extremely helpful.

Just a bit of background. My pool is new and opened in March of this year. My pool was filled but landscaping was not finished yet so lots of sawdust and all manner of construction and landscaping matter entered the filtration system. I have been following the TFP method from day one so the pool has always been crystal clear and sparkling. Love this site! I thought I could get more than 2 months out of my filter without cleaning it but I noticed the flow going down and the pressure going up. The pressure did not go up much, about 5 psi over the 12-13 the filter started at, but I thought, what the heck, I'll see what the cartridges look like and see how hard it is to clean the filter myself.

I pretty much followed Matt's instructions but did not backwash as I don't have backwash plumbed. I made a decision during build that I would just break down the filter and clean it twice a year for my filter maintenance. So with some trepidation, I cleaned the filter last weekend. OMG, I was not prepared for the nastiness I saw on the filter cartridges!

On the right is one of the cartridges after being cleaned. It took me about 15 min per cartridge to get all the funk out. Total time needed was about 3-4 hours, mostly because I was being very methodical and careful with my first filter cleaning. I found tons of plaster minipebbles on the cartidges and in the bottom of the filter. So happy I didn't wait any longer. Pretty straightforward and relatively painless job, albeit time consuming. I'm sure next time will be much faster since I've done it once now.

The only part I was questioning was how much DE to recharge the filter. I went to the store looking for a 1lb coffee can like the manual said, but coffee doesn't come in 1lb cans anymore, doh! Didn't have a DE scoop, so I just weighed 10 lbs of DE on a scale and used that amount to recharge the Quad DE 100 that the manual stated I needed. I hope that's correct. Anyway, if I can do it, anyone can do it.

Thanks again to Matt for posting his method!

 

[jblizzle]

Weighing the DE is by FAR the best approach ... too often the scoops or cans are not really 1 pound.

FYI, 2 times a year may not be enough. We recommend filter cleaning (or backwash) when the pressure rises 20-25% over the clean pressure.

 

[Ocgasman]

Weighing the DE is by FAR the best approach ... too often the scoops or cans are not really 1 pound.

FYI, 2 times a year may not be enough. We recommend filter cleaning (or backwash) when the pressure rises 20-25% over the clean pressure.

Yeah, I'll watch the gauge closely and clean accordingly. I'm hoping that I only have to do it twice a year now that landscaping/hardscaping is done. I don't get much debris in the pool and bather load isn't super high but who knows. Quite frankly, even tho it's not super difficult to clean the filter, it's not something I look forward to doing.

Also, reading your post reminds me that I need to donate to this awesome site! You guys are the best! Have learned a ton. Wished I donated before ordering the TFTest kit.

 

[duraleigh]

That's just "way cool", Matt. I think we might think about an article in Pool School for this thread as well as Smykowski's (another Matt) pictorial on cleaning sand filters. Combine those to a (soon to come....any volunteers?) pictorial on Cart's and we'll have an impressive tutorial.

 

[jblizzle]

That would be great!!!

The test kit discount is a bit of a conundrum ... a new member needs a test kit, but they also are unlikely to "trust" us enough to become a supporter first

- - - Updated - - -

Dave, what about mine of cleaning a grid DE filter? I feel left out

 

[JoyfulNoise]

So this is a quick update - my filter went an entire year without cleaning (March 2016 to April 2017) and I don't backwash. So today I tore it down and cleaned it head-to-toe. The quad cartridges were pretty nasty but everything cleaned off fairly easily. Everything went back together fine. I definitely don't recommend cleaning once per year (I prefer twice per year) but it's really nice to have enough margin in the filter to know it can go that long. Over the entire year my pressure rise was just starting to top out at 25% over clean pressure.

Interestingly, I had to use a Leslie's "low dust" DE (24lbs bag) instead of my typical DE from Patio pools because their satellite store near me closed. I preferred the Patio stuff because it came in 10lbs bags which is perfect for a full tear down. The low dust stuff is a little funky - it's clumpy like when you add some liquid to flour in a blender and the flour initially starts to clump into little balls. The bag says that it is pool grade DE so my guess is they must hydrate it a little to get it clumpy. Personally I'm going to try to find another source of the 10lbs bags of good old fashion cancer causing dusty DE....

***I know, I need to fix the original post to this thread because my Photobucket account got wiped out and now all of my old Photobucket links are broken. Leebo has the original images loaded in the TFP Photo Gallery, I just need to edit and fix the links.

 

[Jimrahbe]

Matt,

Coincidently, I just cleaned my standard cartridge filters two days ago. I also do the "twice-a-year" cleaning.. Once a year would be pushing it for me...

I was curious if you use the "Filter Flossser". Like this... http://www.backyardpoolsuperstore.com/Filter-Flosser-Filter-Cartridge-Cleaning-Tool_p_24212.html?gclid=CL3CwIb5n9MCFdK6wAodnzcFWg

I find it works work pretty well for me. Not sure it is any more effective than a hose end sprayer, but it does keep the back-splatter down.

Thanks,

Jim R.

 

[JoyfulNoise]

Jim,

That wouldn't be too useful for a quad cartridge as there are far fewer pleats to clean and the open area between the folds is big. The cartridges themselves won't filter anything. They are just the spun polypropylene scaffolding on to which the DE adheres. For cleaning, I just use a standard garden hose spray nozzle with selectable spray pattern. "JET" and "SHOWER" patterns work fine. It takes a little work with the spray to dislodge all the caked-on DE but it's not hard.

And, as I learned from previous experience, KEEP YOUR MOUTH CLOSED WHEN SPRAYING


Sent from my iPhone using Tapatalk

 

[Jimrahbe]

Matt,

I went back and looked at a picture of a DE cartridge and what you say makes perfect sense.

I have two pools that have old style DE filters with Grids.. I never backwash them and clean them twice a year.

So what is the advantage to the cartridge style DE filters? Are they generally just bigger?

The grids seem pretty easy to clean, but a lot harder to put back together...

Thanks,

Jim R.

 

[JoyfulNoise]

Matt,

I went back and looked at a picture of a DE cartridge and what you say makes perfect sense.

I have two pools that have old style DE filters with Grids.. I never backwash them and clean them twice a year.

So what is the advantage to the cartridge style DE filters? Are they generally just bigger?

The grids seem pretty easy to clean, but a lot harder to put back together...

Thanks,

Jim R.

Hey Jim,

Saw this last night but fell asleep putting the kiddos to bed....ah the dad-life....

I really like the quad cartridge design by Pentair, I think they did a really good bit of engineering with this filter. Even after backwashing the filter, the dirty and coated cartridges probably weigh 15-lbs each since they are soaked with wet DE. I can't imagine how heavy a grid-style assembly must be to lift out of their standard FNS filter. That alone is enough for me to say "no way, not ever!". The Quad system goes up to 100 sq ft and I think the FNS filters top out at 60 sq ft. However, I do think the FNS style DE filters have higher throughput (higher flow at lower pressure) but I don't think it is much of a difference. Perhaps Mark can expound on the fundamental hydraulic differences between the two styles.

If I were asked to pick a new filter tomorrow, I'd probably go with a Clean & Clean cartridge filter because the extra step of recharging the DE has gotten "old". However, if I had to choose a DE filter, I would choose a Quad style hands-down! I think they are much better than the grid style, at least in terms of maintenance.

One thing to mention is the cost - each Quad cartridge for my filter (the QUADDE-100) runs about $140 or so should they ever need replacement. So, if you had to replace all of the Quad cartridges at once, that would be half the cost of a new Quad filter. That's pretty expensive BUT I'm on year 4 with them and they are still in great shape. This is also where I think the "no backwashing rule" helps - not backwashing them takes a lot of stress off of them and avoids blowing them out. I bet if I backwashed as much as the pool store tells me to ("absolutely EVERY month or else you'll get algae..."), the cartridges would be wrecked in two seasons.