Filter delivers dirty de

[FRANCIS]

My Hayward Perflex EC65 sends a temporary plume of dirty DE media into the pool thru the eyeball return jets after the 1.5 HP pump has been off for a while. I removed and inspected the rubber gasket and every grid finger and found no damage / tears / holes / cracks. Same for the grid plates, bump shaft o-rings. I even tried replacing the tank check valve. Maybe I should try the fiber type of media instead of DE powder?

[SunnyOptimism]

Does the filter have a plunger-style backwash valve or a multiport valve?

I'm thinking maybe there's a leak in your backwash valve...just my opinion FWIW...

[CarlD]

I don't know much about DE filters but I do know that changing media won't fix a basic problem. I'm wondering, if in addition to SO's idea, if your pump is rated for a higher output than your filter's input, which is a common problem. A 1.5hp pump CAN be too strong, especially if it's a full-rated pump (most in ground pool pumps are). How big is your pool and what kind of pump is it?

You can go to Hayward-Pools.com and look up your owner's manual. It has several suggestions of possible causes of DE going back into your pool.

[SunnyOptimism]

+1 to @CarlD !!!

Yeah, before spouting off I should have asked for more details on the pump/filter combo. I have a full rated, variable speed 3HP IntelliFlo pump. I also have the biggest DE filter possible. Even then, I run my pump on the slowest speed most of the time. I only use the highest speeds for quick vacuuming.

What kind of pump do you have? Horsepower? Single-, two-, variable-speed?

What's the sq-ft area of your filter and its nominal flow rate?

[FRANCIS]

Pool - Pacific in-ground vinyl 27,500 gal
Filter - Hayward Perflex EC65 67 gpm rating with 27 square feet effective filtration area.
Pump -Hayward Super Pump 1.5 hp single speed rated at 65 gpm with 30 feet of head resistance.
There is no 'backwash action'. The filter features a bump handle that regenerates the DE by jogging the grid - something like a piston.

[CarlD]

Pump: 65gpm with 30' of head.
Filter: 67 gpm.

So if you do NOT have at least 30' of head, your pump is probably exceeding your filter's max. In any case, IMHO, the filter is too small for the pump and you need a bigger cap filter or smaller pump.

[SunnyOptimism]

@CarlD nailed the pump/filter sizing issue. 30' of head is approximately 13psi pressure. What's your normal system pressure?

Also, I'd like to chime in on the DE issue. Your original post stated that DE was coming back through your return lines into the pool. I took a look at the filter manual and there is a built in check valve in the filter. The troubleshooting section clearly states that DE returning to the pool after pump shutdown could be a result of a bad check valve.

Have you disassembled the discharge elbow and confirmed the check valve is operable?

[SunnyOptimism]

Please IGNORE my last post!

You clearly stated that you replaced the check valve. I did not read your original carefully enough and missed that point. My apologies.

[FRANCIS]

yes - i spent 50 dollars on a check valve for nothing.

[SunnyOptimism]

So if I understand the problem correctly, you only get DE out of your returns when the pump shuts off, correct? During normal pump operation, the water coming out of the returns is clear, correct?

[FRANCIS]

Incorrect - Dirty DE enters the pool thru the return [eyeball jets] momentarily when the pump starts up after a period of downtime. When I say 'momentarily', it lasts a few seconds - enough for a big ugly plume of green to emerge. Once the DE re-coats the grid, the water runs clear. This is killing me. I can't allow the time clock to automatically start the pump. I need to do it manually so I can divert the slug of dirty water thru a drain temporarily.

[CarlD]

Unfortunately, it looks like most of our experts on plumbing and filter issues (other than sand) may have checked out for the season.

[SunnyOptimism]

I know this sounds like generalizing but something has to be cracked, loose or torn in some way. Or there's an o-ring or gasket somewhere that is not sealing.

What you're describing is a transient situation where the pressure at start up is low allowing the "thing" that is not sealing to pass DE. Then, once the system pressurized and the DE re-coats everything, the "leak" is plugged. Remember that DE is just extremely fine silicate shells of dead marine algae. The DE particles can be as small as 3 micrometers in size but are typically 10-100micrometrs. This powder is so fine that even the smallest tear, crack or unsealed surface can allow it to pass.

So, sorry for being overly broad and not very helpful, but something is not sealed right. Looking at the design of this Hayward filter, I guarantee there's a well known engineering flaw in there somewhere. I have a Pentair QuadDE filter which is just a hybrid cartridge filter that uses DE. I like the design as there are only four cartridge units that need to be properly seated and sealed making it a low complexity design. Also, there's no mechanical bumping, just backwashing.

Keep posting results and I hope someone else here with a similar DE filter can chime in to help.

[FRANCIS]

When the pump kicks on after being off for some time, the DE particles and the dirt particles that were laying at the bottom of the filter tank are now racing back up to the grid fingers - correct? But in doing so, some of the dirt passes thru the fabric before the DE does a complete re-coat. So maybe this filter has an inherent design flaw and it's been doing this blowback since day one - but i have only noticed it recently when i walked past the returns after i activated the pump?

[CarlD]

I doubt it's an inherent design flaw. More likely a defective unit or a too-big pump. It's also possible it was initially set up wrong and was damaged.
I don't know if a total tear-down and rebuild is worth it, or if you should just consider replacing it with a bigger capacity unit, and consider switching to a sand filter.

[SunnyOptimism]

When the pump kicks on after being off for some time, the DE particles and the dirt particles that were laying at the bottom of the filter tank are now racing back up to the grid fingers - correct? But in doing so, some of the dirt passes thru the fabric before the DE does a complete re-coat. So maybe this filter has an inherent design flaw and it's been doing this blowback since day one - but i have only noticed it recently when i walked past the returns after i activated the pump?

I don't think that's how my DE filter works. My Pentair has four cartridges in it that the DE sticks to and accumulates on. Perhaps some DE floats off the cartridges after pump shutdown, but I believe most of it stays on the cartridges.

If Hayward intentionally designed their filter to lose the DE costing after pump shutdown, then I'd say that's a pretty poor design. However, since it is a bump-style DE filter, that just might be the case.

With all that said, the fingers should not let DE pass through them. If that is truly what's going on here, then I'd say you need to replace the grid assembly. Is that a replaceable part? Any idea how much that costs? As annoying as it is, I think this warrants a call to Hayward to see what they recommend.

[FRANCIS]

it's cheaper to buy a new filter than replace the 120 flex tubes @ 6 dollars each. Do you really think Hayward would entertain my phone call? I don't even see a phone no. in the user manual.

[CarlD]

From Hayward-pools.com:

Contact Hayward Residential Pool

Contact us by phone:

(908) 355-7995 (U.S.)

Mon-Fri, 8 AM – 5 PM

Contact us by letter:

Hayward Pool Products
Attn: Technical Services
One Hayward Industrial Drive
Clemmons, NC 27102

[FRANCIS]

Really like this unit. What's the logic in an oversized pump causing the problem? Wouldn't it force DE thru the fingers ALL the time? Do not want to re-pipe system. Must figure out how to solve this issue. just spent beaucoup dollars repairing extensive pool wall damage from last winter's brutality.

[CarlD]

OK. It MAY NOT be that your pump is too big and you have another problem. But a too-big pump for the filter is ALWAYS bad, and always a potential source of damage to the filter, regardless of DE, sand or cartridge.

Again, I'm not a DE filter expert--I only know the general principles, so I cannot help with details of what might be wrong.

Unless you have metal pipes (and nobody has used that for a long time, PVC plumbing is very easy and very quick. I've replumbed my pool as I've changed things over the years many times...when I didn't like how the pump to filter flow worked, when we added a deck and moved the pump and filter about 15' (the tough part was re-routing the 240v wiring for the pump), and when I added the SWCG before the 2013 season (again, additional electrical work was the bear).

So PVC is easy to work with and TigerFlex, the flexible PVC, gives you even more options. PVC and/or TigerFlex, Schedule 40 fittings, cleaner, primer (or cleaner/primer), glue, and a hacksaw are all you need. Most of it, except the TigerFlex, are at Home Depot or Lowes. So I dry fit it all first, cutting my PVC to length. When I'm satisfied, I use the cleaner on the pipe and the fitting, then wipe on the primer, then the glue. Stick the pipe into the fitting, give it a 1/4 turn to where you want it and move on. Nothing to it.

[FRANCIS]

That's actually a cool idea - using tiger flex above ground.

[CarlD]

Here is some of the TigerFlex running to my skimmer and low drain. Since I drain it and put it away in the fall, in the basement, I have no problem leaving it on the ground. While I've re-plumbed a few times, this TF came with the pool 12 years ago and is still good. You can see the quick-connect/ball valves at the low drain and skimmer, though the handle on the low drain ball valve is gone. Since I'm rebuilding the pool this winter those ball valves will be replaced, but the TF won't be. It works exactly like hard PVC, just a little harder to cut evenly.

Unfortunately, too many pool installer treat TF like it's hose. It's not. So they put barbed fittings INSIDE the TF with hose clamps...and it inevitably leaks. (the orig installers did that and I had to replace all the barbed fittings because it leaked just after they drove away!) But if you use glue-on Schedule 40 fittings, just like hard PVC, it doesn't leak. I've NEVER had a leak from the Sch 40 on the TF.
On caveat: You cannot bury TigerFlex, unlike hard PVC or the black flexible plastic pipe used for sprinkler systems and wells.

https://lh6.googleusercontent.com/-eW0Chrct6Lg/VA7deTsKdeI/AAAAAAAAAEE/WblfzFJu2bA/s912/20140903_183417.jpg

[FRANCIS]

Awesome!
Hey - did you know you can cut tiger flex with a length of mason's line?
And who says TF is not meant for direct burial? I dug some tiger flex up that was buried for 20 years and it's still fine.
I agree 100% about not using barb fittings - plus they reduce the cross-sectional area.

[FRANCIS]

ok - so i called hayward with your posted info and got a tech right away. thank you. he thinks the algae cells that i vacuumed up are passing thru the mesh while the DE is trying to re-coat.

[CarlD]

Awesome!
Hey - did you know you can cut tiger flex with a length of mason's line?
And who says TF is not meant for direct burial? I dug some tiger flex up that was buried for 20 years and it's still fine.
I agree 100% about not using barb fittings - plus they reduce the cross-sectional area.

Learn something new every day! I usually just cut it with an 18V Sawzall. There's a wire cutter like a mason's line, plumbers use for cutting PVC in tight places. Does the mason's line cut through the spiral ribs cleanly?

As for the cross-section: there's other flexible hose, usually clear, that works just fine with the same barbed fittings. Still, gluing's the best.

[FRANCIS]

Clean as a whistle. I had to resort to that method when i dug a post hole right onto a buried obsolete tigerflex. Had to sever the tigerflex to allow hole digging to continue to a deeper depth. Tried welding a sawzall blade to the squashed end of a 3/4" piece of thinwall, but it kept binding. Mason's line to the rescue!! Once you get it going - do not stop or else it sticks. But when it cools, you can continue.

[FRANCIS]

I looked at Pentair's Quad DE / cartridge filter user manual. it says a brief cloud of dirt is characteristic for diatomite filters. Maybe i can incorporate a motorized valve that reverts discharge water back into the return for 10 seconds during start-up.
http://www.pentairpool.com/pdfs/178658EQuadOM.pdf

[SunnyOptimism]

I looked at Pentair's Quad DE / cartridge filter user manual. it says a brief cloud of dirt is characteristic for diatomite filters. Maybe i can incorporate a motorized valve that reverts discharge water back into the return for 10 seconds during start-up.
http://www.pentairpool.com/pdfs/178658EQuadOM.pdf

Hey @FRANCIS, how are you? Did you get a new DE filter?

Yes, I have a QuadDE filter and I can confirm that it does that but only for a short period of time after initial start up, deep cleaning or backwashing. This past fall, I completely tore down my filter and cleaned out all the old DE from inside the filter body and from the cartridges (takes about half a day). I then restarted my system and performed a full DE recharge (about 10lbs of DE or 20 plastic scoops). For a few weeks after the restart, I would see a cloud of DE come out of the returns for no more than 30sec or so. Basically what is happening when you clean the filter is that you remove all of the DE from the nylon fabric mesh of the cartridges (backwashing partially does this as well). Then, when you start using your filter, it takes time for the DE/water mixture to build up a coating on the fabric surface. Eventually it does and over time the DE eventually gets stuck in place on the nylon and no longer falls off when the pump is not running. It took about a month, but the DE gradually stopped coming out of the returns and I no longer see it anymore during pump start up.

Here's the trick to maximize the likelihood that the DE coating stays stuck - when recharging the DE after a tear down clean or a backwash, add the DE back very slowly and only 1lb at a time. Take a a 1lb plastic scoop, add the DE to a 5 gal bucket of pool water and mix it up to a slurry. Then pour the mixture very slowly into the skimmer. After that, wait a few minutes before adding the next pound. It also helps if you have a 2-speed or variable speed pump to run it on the highest speed so that you are operating at the highest possible flow rate. DE has a tendency to settle out of water fairly quickly and you want the DE to hit the cartridge material not just settle to the bottom of the filter tank. Using the slow add procedure will maximize the amount of DE that gets embedded into the cartridge and reduce the DE blow back.

If you constantly see lots of DE coming out of the return or it takes longer than a few minutes to stop, then there could either be a hole in one of the cartridges or something is loose and not seated properly.

[FRANCIS]

no, i did not get a new unit. especially after reading blowback is normal. the methods you describe take patience. i have a limited amount of patience. i need fast results. i will probably try the non-diatomite media this year - you know - the fiber stuff. if that fails, i will see if i can scrounge up a recycling valve [motorized].

[JimK]

Hmmm....I never noticed DE blowback with my Hayward Pro Grid 6020 DE filter (installed in 2004) even after a backwash/recharge.

PS - After backwashing, per Hayward manual, I do run it with the multi port valve in the Rinse position before returning to the normal Filter position. Perhaps this is why I don't get any DE blowback in the pool?

[SunnyOptimism]

no, i did not get a new unit. especially after reading blowback is normal. the methods you describe take patience. i have a limited amount of patience. i need fast results. i will probably try the non-diatomite media this year - you know - the fiber stuff. if that fails, i will see if i can scrounge up a recycling valve [motorized].


You might be happier with a cartridge filter - no DE or Fiber to recharge and you get slightly better particulate performance than a sand filter.



Hmmm....I never noticed DE blowback with my Hayward Pro Grid 6020 DE filter (installed in 2004) even after a backwash/recharge.

PS - After backwashing, per Hayward manual, I do run it with the multi port valve in the Rinse position before returning to the normal Filter position. Perhaps this is why I don't get any DE blowback in the pool?

That could be it but I will say the effect is very hard to notice unless your looking right at the returns when you start the pump. It kind of looks like light-grey colored water coming out for a few seconds.

I also think that this is a consequence of the Pentair QuadDE design as it is basically a quad cartridge filter that has modified cartridges that a capable of holding DE. It is not the old style finger-type or vane-type DE filter. It's actually a really nice design as it is super-easy to take apart and the cartridges are pretty robust. Also, if you get tired of DE, you can convert it easily to a cartridge filter.

That being said, once you recharge the DE, it only takes a short period of time for the blowback to stop. At least that has been my experience it after three season.

[FRANCIS]

I overhauled the DE filter and found no tears etc. But I had three grid fingers with slight miudpoint weave damage which I wrapped shut with electrical tape a few years ago. So this time I decided to replace said fingers (3) and now I get no blowback. (at least not yet) There is no way so much dirty DE could have snuck under the tape. I am at a loss to explain this issue any further. Although there is one thing I learned in life, when you can't seem to figure out the problem with a mechanical device, overhauling it seems to do the trick.