DE filter requires cleaning too often

[archer636]

when I first got my DE filter, I could go 2-3 months before backwashing/cleaning. But nowadays (3 years later) I have to do it every 3-4 weeks (judging based on pressure gauge as well as loss of polaris power). Is there any reason filter would need cleaning more frequently than before?
(I do remove the grids on occasion and do a full cleaning, not just backwash that could result in build up)

 

[ajw22]

Depends how you are doing the full cleaning. You cleaning with TSP and then diluted acid solution?

DE Filter Use and Care - Further Reading

www.troublefreepool.com

 

[Jimrahbe]

Archer,

Has your clean pressure also gone up? Seems to me that either you have a low level algae outbreak that you can't see yet, or your grids are scaling and not passing water like when new...

If the clean pressure is the same, then I would suspect algae.. If the clean pressure has gone up, I would suspect the grids..

Thanks,

Jim R.

 

[sean.a.hyde]

Archer,

Has your clean pressure also gone up? Seems to me that either you have a low level algae outbreak that you can't see yet, or your grids are scaling and not passing water like when new...

If the clean pressure is the same, then I would suspect algae.. If the clean pressure has gone up, I would suspect the grids..

Thanks,

Jim R.

I will second this comment. I was about to tear my hair out having to backwash my filter every few weeks. Then I became TFP-enlightened and measured my stabilizer over 150. I had been keeping the chlorine level at 4ish. The pool looked beautiful and sparkling clean... but I think that was only because I was running my pump 24/7 through my DE filter (and got pretty lucky). I raised the chlorine to the correct level, and didn't have to backwash the filter the rest of the season(!).
Obviously, your situation may be different, but wanted to share my experience.

 

[archer636]

Archer,

Has your clean pressure also gone up? Seems to me that either you have a low level algae outbreak that you can't see yet, or your grids are scaling and not passing water like when new...

If the clean pressure is the same, then I would suspect algae.. If the clean pressure has gone up, I would suspect the grids..

Thanks,

Jim R.

what do you mean by clean pressure?

the polaris pressure goes down when filter pressure goes up.

 

[Texas Splash]

It's always good to know your filter clean pressure - without any other devices connected. This give you as the owner a baseline to go by for future reference. For example, if you just cleaned the grids and your clean filter pressure at start-up is say 12 psi, then you know over the coming days/weeks that if it rises by 25% or more from that 12 psi, it's time to backwash, clean, or check to see if something is wrong (algae).

 

[archer636]

It's always good to know your filter clean pressure - without any other devices connected. This give you as the owner a baseline to go by for future reference. For example, if you just cleaned the grids and your clean filter pressure at start-up is say 12 psi, then you know over the coming days/weeks that if it rises by 25% or more from that 12 psi, it's time to backwash, clean, or check to see if something is wrong (algae).

I see. The clean pressure has gone up slightly over 3 years (maybe 2 psi) so it's probably not the grids....

 

[Texas Splash]

The clean pressure has gone up slightly over 3 years (maybe 2 psi) so it's probably not the grids....

Just to make sure we're all thinking the same ......... When you say your "clean (starting) pressure hasn't changed much over the past 3 years", that's one thing. But in post #1 you say you have to backwash every 3-4 weeks. So that's the change we are referring to. The spike in filter pressure from the time you last cleaned it to now. When we see/hear of a filter that requires backwashing/cleaning more frequently than normal, we start to look at the beginning signs of algae.

 

[archer636]

Just to make sure we're all thinking the same ......... When you say your "clean (starting) pressure hasn't changed much over the past 3 years", that's one thing. But in post #1 you say you have to backwash every 3-4 weeks. So that's the change we are referring to. The spike in filter pressure from the time you last cleaned it to now. When we see/hear of a filter that requires backwashing/cleaning more frequently than normal, we start to look at the beginning signs of algae.

what I meant is that immediately after backwash (or full clean), the pressure is around 22psi (when I first got the filter, it was 20, so "clean" pressure has not changed much). Problem is, it raises very quickly after that to 27-28 psi (it used to take longer)

 

[Texas Splash]

Problem is, it raises very quickly after that to 27-28 psi (it used to take longer)

Yep, that's exactly what Jim and I suspected. So there really are two possibilities at hand:
1 - After 3 years or so, your grids are getting coated with oils and such that are beginning to effect filter pressure that simple backwashing can not correct. Or .....
2 - You have the on-set of algae beginning. It is very common for algae to not be visible to the owner in its early stages. The first indication of algae is almost increased filter pressure, followed by cloudy water, then eventually the dreaded "green".

I would recommend a couple things..... First, post a full set of test results with your K-2006 so we can see exactly how the levels look. In addition, it's easier to do an Overnight Chlorine Loss Test before tearing down the filter, so I'd do the OCLT as well. If you pass the OCLT, then you may need to look at any options to deep clean those grids.

Maintenance and Cleaning of Pool Filters

Maintaining your swimming pool filter system is important. Learn how to clean and maintain your pool filter at low cost & enjoy a Trouble Free Pool.

www.troublefreepool.com

DE Filter Use and Care - Further Reading

www.troublefreepool.com

 

[archer636]

Yep, that's exactly what Jim and I suspected. So there really are two possibilities at hand:
1 - After 3 years or so, your grids are getting coated with oils and such that are beginning to effect filter pressure that simple backwashing can not correct. Or .....
2 - You have the on-set of algae beginning. It is very common for algae to not be visible to the owner in its early stages. The first indication of algae is almost increased filter pressure, followed by cloudy water, then eventually the dreaded "green".

I would recommend a couple things..... First, post a full set of test results with your K-2006 so we can see exactly how the levels look. In addition, it's easier to do an Overnight Chlorine Loss Test before tearing down the filter, so I'd do the OCLT as well. If you pass the OCLT, then you may need to look at any options to deep clean those grids.

Maintenance and Cleaning of Pool Filters

Maintaining your swimming pool filter system is important. Learn how to clean and maintain your pool filter at low cost & enjoy a Trouble Free Pool.

www.troublefreepool.com

DE Filter Use and Care - Further Reading

www.troublefreepool.com

thanks- I will do that and report. Soaking the grids in acid and TSP sounds like a huge pain- I may just order new grids if it comes to that.

 

[Jimrahbe]

Archer,

If the grids are over 5 years old, I would also just order new ones....

A clean pressure of 20 lbs. seems pretty high to me... Do you have a heater or other stuff in between the filter and the pool? How may returns do you have and what size eyeballs are on them?

Most DE filters that I have seen have a clean pressure of about 10. Of course all pools and plumbing are somewhat different so there is no way to tell. It could just be that you have a 1.5 HP pump running full speed.. I suggest that you look into a VS or 2-speed pump.. It would almost pay for itself in electrical cost and let you go longer between cleanings... I have two rent house pools that I never backwash.. I just clean the filter twice a year.. My filter pressure is about 5 lbs. Pumps run 24/7 for less than $20 bucks a month.

Thanks,

Jim R.

 

[ajw22]

A clean pressure of 20 lbs. seems pretty high to me...

My normal clean pressure on my Pentair DE filter is around 20 with a SS pump. I need to backwash by the time pressure gets to 28-30 PSI.

 

[JJ_Tex]

My clean pressure is around 20 psi as well and a brand new system. I have a variable speed pump, so I took my clean pressure reading at max RPMs (3400). I've only backwashed twice, but did it when the pressure hit 25.

With that said, at my normal run speed (1600 rpms), my pressure is 10 or less.