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Thread: SLAM! Shocking with a D.E. Filter?

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    SLAM! Shocking with a D.E. Filter?

    Hi everyone,

    My pool is a swamp...

    I've been having a series a serious issues with my pool equipment in the past 3 months and had to redo a lot of the plumbing which prevented me of taking care of my chemistry as usual. I'm trying to shock the pool back to life but I can't seem to figure out the process with my DE filter. With cartridges I used to clean the filter once a day until pool was clear, but with the DE, after about 1 hour, the water flow is almost stopped until I backwash. Now when I backwash I assume that most of the DE goes at the same time so the question is, Am I supposed to re-load DE every couple hours? Also is this normal? I have to be at work and cannot reasonably be around the pool cleaning my filter that frequently.

    By the same token, is liquid chlorine more efficient to shock that "shock" powder? Should I also add Algea treat in the mix?

    Thanks for your help.
    IG * pebble * 23,700 gal * DE Pro-Grid 3620 * Spa * NO-SWG

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    Mod Squad JohnT's Avatar
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    Re: SALM! Shocking with a D.E. Filter?

    Yes, it's pretty well normal to have to frequently backwash and add more DE when the pool has algae.

    The best option is to run with the filter on recirculate while you are gone, then filter while you can attend to it.

    Liquid chlorine doesn't do anything for sanitation that powdered chlorine doesn't do, but the powdered stuff either adds calcium or CYA to the water. Both can cause problems pretty quickly.
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    Re: SALM! Shocking with a D.E. Filter?

    +1 for John. Let the chlorine kill a good bit of algae while pumps are on recirculate. Then once pool starts to turn or when you feel ready let the DE filter out cloudy white dead algae. I bet it works quickly for you. Keep brushing during the process.
    In ground 25,000 gallon - vinyl liner - Sand filter - residential pool
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    Patrick_B's Avatar
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    Re: SALM! Shocking with a D.E. Filter?

    Welcome to the forum.

    You've gotten good advice, so I've not much to add. Please let us know how it goes for you, and if we can help. Good luck!
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    Richard320's Avatar
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    Re: SALM! Shocking with a D.E. Filter?

    The shock powders will add either Calcium or CYA to your pool along with the Chlorine. If you raise the CYA, the shock level you need to maintain will also go up, which means you have to add more powder, which adds more CYA, and you end up in a vicious spiral that ends in failure. If your CH level is low, then the Cal-hypo version of the powder is useful, but you're also adding another factor to the balancing equation. This is why we tend to push liquid bleach for the SLAM.

    Yes, your filter will load up fast. Remember to only add 80% of recommended DE after a backwash because it never washes off completely. If you open the filter up and clean the grids 100%, then use the full amount to recharge. When your pool is clear again, I'd recommend a full cleaning.

    If you have a multiport valve that offers Recirculate, you can use that to just keep the water moving while the bleach does its stuff, however you won't see an increase in clarity until it goes back to filter mode to actually strain the algae carcasses out.

    You don't need any additives, bleach alone will clear the pool. Proof:

    first-time-shocking-with-bleach-t45074.html
    pretty-black-pool-t58442.html
    first-time-pool-owner-t61565.html
    a-little-encouragement-for-those-with-algae-and-new-to-bbb-t57137.html
    frog-filled-green-swamp-to-oasis-work-in-progress-t48213-20.html
    before-and-after-t36785.html
    a-final-picture-set-of-how-well-the-bbb-method-works-t33199.html
    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: SALM! Shocking with a D.E. Filter?

    One more for bleach only and this was my personal pool.

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    Re: SLAM! Shocking with a D.E. Filter?

    Wow that's a lot of responses, thanks a bunch. I'll measure my CYA to figure out shock level and add liquid chlorine as needed while filter is set to recirculate.

    How do you know for sure that the algea are dead and the pool is good to go for filtering?
    IG * pebble * 23,700 gal * DE Pro-Grid 3620 * Spa * NO-SWG

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    Mod Squad jblizzle's Avatar
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    Re: SLAM! Shocking with a D.E. Filter?

    As the algae dies, the water will turn from green to grey/white.

    Even after that, you are going to have to clean the filter often.
    Jason, TFP Moderator
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    Re: SLAM! Shocking with a D.E. Filter?

    So 2 weeks later, 20 gal of chlorine, 2 bags of DE and countless backwashing later the pool looks almost OK. It still has that cloudy look to it but it's getting better every day. Now the problem is that I have this very fine powder at the bottom of the pool that won't quit. I tried brushing but the powder goes back down too fast for the pump to pick it up. The barracuda vacuum can't seem to pick it up either. Should I get a professional power vac done?
    IG * pebble * 23,700 gal * DE Pro-Grid 3620 * Spa * NO-SWG

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    Richard320's Avatar
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    Re: SLAM! Shocking with a D.E. Filter?

    Quote Originally Posted by mrethers View Post
    So 2 weeks later, 20 gal of chlorine, 2 bags of DE and countless backwashing later the pool looks almost OK. It still has that cloudy look to it but it's getting better every day. Now the problem is that I have this very fine powder at the bottom of the pool that won't quit. I tried brushing but the powder goes back down too fast for the pump to pick it up. The barracuda vacuum can't seem to pick it up either. Should I get a professional power vac done?
    Why not just buy or borrow a vacuum hose and a vacuum head to attach to your pole? If you have to buy it, it's probably close to what a pool service would charge, and you'll have it, in case you don't get it all the first time.
    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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