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Thread: DE Blowing back into the pool

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    DE Blowing back into the pool

    Hi,

    This year when I opened my pool (Sat the 20th), there was a split in the manifold of my FNS Plus filter. Consequently all of the DE I put into the filter blew back into the pool. I think I made an additional backwash and reload of DE, so probably a total of around 3 pounds, before I realized.

    I bought a new manifold and installed it and carefully checking all of the fins for holes etc before replacing the cartridge. (I bought new fins last year, so they are in good condition).

    My water is cloudy and milky. When I can see the bottom, there is a thin layer of DE. I can brush this up into clouds.

    I've been trying to correct this by putting more DE in and brushing the pool. Does not seem to work.
    Not putting DE and brushing the pool.
    Backwashing frequently in both cases.

    When I backwash, the pressure gauge is at about 15 or so and there is a good flow coming from the jets.
    Then, literally while I stand there over a period of about 1-2 mins, I can watch the gauge go up to about 30 and the flow reduce to almost nothing.

    I can then go and backwash just for about 20 seconds and that the pressure is back to 15 and the flow good. Then the process repeats in a minute or two.


    No idea what to do here!!

    I feel good about the new manifold and its installation. Looks pretty tight.

    Any ideas? Please?

    Thanks in advance
    Phil


    20k pool
    salt system
    FNS Plus DE Filter
    2 hp (i think) pump
    (1) St. Louis, MO. (2) 18-20K kidney shaped (3) DE FNS Plus 48 (4) Salt System (IC40) (5) Pentair Intelliflo 3HP (6) 24 x 7 (7) Dolphin M4

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    JasonLion's Avatar
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    Re: DE Blowing back into the pool

    If you stop running the pump overnight all of the DE that got into the pool should settle down to the bottom. Then you can vacuum it to waste. When vacuuming, move slowly being careful not to stir it back up into the water. You may need to do this two or three times to get it all, as some will go back into the water no matter how careful you are. Once you get nearly all of it, the filter pressure won't go up nearly as quickly and things will start getting back to normal.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  3. Back To Top    #3

    Re: DE Blowing back into the pool

    Thanks for the quick response Jason,

    I'll turn off the pump now and then try and vacuum in the morning.


    Question though.

    Under normal circumstances when I pour a thick mixture of water and DE into the pool (after backwashing) the DE sticks to the fins in the filter and all is good.

    What is different about DE being suspended in the pool water and then making its way to the fins. Why doesn't it all stick and clear the water.

    Thanks again
    Phil
    (1) St. Louis, MO. (2) 18-20K kidney shaped (3) DE FNS Plus 48 (4) Salt System (IC40) (5) Pentair Intelliflo 3HP (6) 24 x 7 (7) Dolphin M4

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    JasonLion's Avatar
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    Re: DE Blowing back into the pool

    The DE is getting caught by the filter, which is why the filter pressure is going up so quickly. If you wanted, you could simply backwash each time the filter pressure went up, and you would eventually filter nearly all of it out (some would still settle to the bottom). However, that would take time, and lots of backwashing/recharging. Letting it settle and then vacuuming to waste gets it out of the pool more quickly and with less total effort.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

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    Richard320's Avatar
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    Re: DE Blowing back into the pool

    Maybe it's not backwashing completely, which could make your innards look like the filter in this thread.
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

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    Re: DE Blowing back into the pool

    Wow and Wow.

    No my innards are pretty clean compared to that. Whew.

    I spent large parts of the weekend vacuuming and taking my filter cartridge out and hosing it down and then running the filter (no DE).

    Almost can see the bottom on the deep end and I can see the bottom on the shallow end. With the light on the water looks just a little cloudy, much better than last week.

    I still have some scattered DE on the bottom to vacuum up yet. Will do that tonight.

    Late yesterday afternoon, decided to try putting DE into the filter again. So with my Wife watching one of the Jets, I slowly poured DE into the skimmer and guess what, no cloud of DE pouring back into the pool.

    By this morning the flow had significantly reduced.

    Tonight I'll:

    Vacuum to waste again
    Take out the cartridge and hose it clean
    Put more DE in.
    Run it filtering

    Phil
    (1) St. Louis, MO. (2) 18-20K kidney shaped (3) DE FNS Plus 48 (4) Salt System (IC40) (5) Pentair Intelliflo 3HP (6) 24 x 7 (7) Dolphin M4

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    JasonLion's Avatar
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    Re: DE Blowing back into the pool

    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

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