Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 6 of 6

Thread: Backwashing Mystery --- Need New Filter Elements???

  1. Back To Top    #1

    Backwashing Mystery --- Need New Filter Elements???

    My in ground, plaster/gunite pool really takes a beating over the winter here in Northern Virginia. It is bordered on two sides by tall trees, and all that stuff falls on it, of course. I always have it covered, but the cover is permeable, and it has less than a perfect fit, so when I open in the spring, I have lots of STUFF in the pool. Aside from grit, dirt, pine needles and leaves, it's a rare opening where there are not one or two dead critters. And of course algae! Nonetheless, for about a ten year period ending in 2015, I would use my net, my Polaris 380 pool sweep, and the Pentair FNS 60 pool filter to get things ship shape. All during that period, I would achieve good water quality, with all foreign material removed, in just 3 backwashes of the filter. It is large for my size pool (~14,000 gallons), but that is what I wanted.

    My filter runs at 9-10 PSI when clean and freshly charged. I backwash when it hits 18 to 20.

    Of course, along with all the filter ops, I followed the TFP regimen for water chemistry.

    Last year, I noticed that to get the pool just right required 4 backwashes. One year later, this afternoon I'll probably complete my 6th backwash of this opening event. Something has changed, and I am not at all sure what it is. I completely disassemble the filter each fall and clean it; there is no evident damage to anything that I can note. Anyone have any ideas?
    14,000G Gunite pool, 1-1/2 HP Challenger Pump + 1HP Booster Pump, Waterfall feature, Pentair 60 DE Filter, Polaris 360 Pool Sweep
    Manassas, VA

  2. Back To Top    #2

    Join Date
    Aug 2012
    Location
    Mt. Airy, MD
    Posts
    23

    Re: Backwashing Mystery --- Need New Filter Elements???

    When you say that you clean your filter every fall, do you mean you hose the old DE out or do you descale and degrease it? Minerals can build, and oils from skin and sunscreen also start to clog them after a while.

    I am in Maryland and also get through the whole year with 3 backwashes on my DE filter. 6 is a lot....

  3. Back To Top    #3

    Re: Backwashing Mystery --- Need New Filter Elements???

    Quote Originally Posted by iadams View Post
    When you say that you clean your filter every fall, do you mean you hose the old DE out or do you descale and degrease it? Minerals can build, and oils from skin and sunscreen also start to clog them after a while.

    I am in Maryland and also get through the whole year with 3 backwashes on my DE filter. 6 is a lot....
    I've never descaled and degreased. Perhaps that is the problem. The filter is now 13 years old. I do completely disassemble and hose down everything. What's involved in descaling and degreasing?
    14,000G Gunite pool, 1-1/2 HP Challenger Pump + 1HP Booster Pump, Waterfall feature, Pentair 60 DE Filter, Polaris 360 Pool Sweep
    Manassas, VA

  4. Back To Top    #4
    Mod Squad pooldv's Avatar
    Join Date
    Aug 2012
    Location
    DFW, TX
    Posts
    23,998

    Re: Backwashing Mystery --- Need New Filter Elements???

    I don't know a lot about DE filters but here is more info from Pool School.
    Pool School - Maintenance and Cleaning of Pool Filters
    and
    Use and care for DE filters
    TFP Moderator
    If TFP helped you or saved you money - Become a TFP Supporter! <--Click here
    2012 build and pics, 20k gal gunite, black onyx pebblesheen, OK flagstone, IntellifoVS, cart filter w/Pleatco, IC40 SWG, Solartouch, 5 12'x4' solar panels, HP50HA heat pump, 8mil solar cover, borates, TF-100 test kit, SONOS, Doheny's Discovery Robot, hot tub on bleach

  5. Back To Top    #5

    Re: Backwashing Mystery --- Need New Filter Elements???

    Quote Originally Posted by pooldv View Post
    I don't know a lot about DE filters but here is more info from Pool School.
    Pool School - Maintenance and Cleaning of Pool Filters
    and
    Use and care for DE filters
    Thanks very much. I was up to speed/in compliance with almost all of this until I got to the last part, the one about the degreasing/descaling:

    "To chemically clean the grids/ nest:
    1) Have a bucket/container large enough to hold the entire assembly - A large plastic garbage can works well.
    2) #1 Add some TSP (tri-sodium-phosphate) to the water or some electric dishwasher detergent to the water and soak the grids for at least 3 hours - this will "de-grease" the membranes and is the first step in cleaning them, rinse with hose and get ready for step 3.
    3) Dump the container, refill with water and add muriatic acid to the water so that you have a 10:1 water:acid mixture and soak the grids for at least another 3 hours, this will clean any calcium off of the grids. Rinse grids again and reinstall them in the filter.
    4) Now, run pump and bleed off the air from the filter and add 100% of the DE the filter calls for."

    This procedure is pretty much where I draw the line! Looking at reviews of replacement grid assemblies on Amazon, which contain a number of user scenarios similar to mine, I decided its time for new grids. My old ones are 13 years old --- their days are done.
    14,000G Gunite pool, 1-1/2 HP Challenger Pump + 1HP Booster Pump, Waterfall feature, Pentair 60 DE Filter, Polaris 360 Pool Sweep
    Manassas, VA

  6. Back To Top    #6
    Mod Squad pooldv's Avatar
    Join Date
    Aug 2012
    Location
    DFW, TX
    Posts
    23,998

    Re: Backwashing Mystery --- Need New Filter Elements???

    LOL! I'd say you got your money's worth!
    TFP Moderator
    If TFP helped you or saved you money - Become a TFP Supporter! <--Click here
    2012 build and pics, 20k gal gunite, black onyx pebblesheen, OK flagstone, IntellifoVS, cart filter w/Pleatco, IC40 SWG, Solartouch, 5 12'x4' solar panels, HP50HA heat pump, 8mil solar cover, borates, TF-100 test kit, SONOS, Doheny's Discovery Robot, hot tub on bleach

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •