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Thread: Crystals Everywhere - Any Ideas?

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    Join Date
    May 2008
    Location
    Central New Jersey
    Posts
    7

    Crystals Everywhere - Any Ideas?

    Hello, Everyone.

    I'm a newbie to managing my own pool and have a somewhat unique problem (at least I haven't seen anybody post something like this recently)...

    Pool stats:

    Volume: about 15,500 gallons
    Surface Area: 500 square feet
    Type: Inground, concrete, with Hydrazzo finish
    Filter: DE (Hayward 6020)
    Chlorinator: The Liquidator (liquid chlorine feeder)
    In-pool Vac: Polaris 380

    When our pool was being built in summer of 2007, the builder plastered (Hydrazzo) and filled the pool before he backfilled the area around it. It's probably needless to say just how much dirt (of the red clay variety) got in the pool when this happened, but it caused plenty of staining which he promised to take care of at the end of the season with an acid wash. So, in mid-September, the pool was drained, acid washed, and refilled. Since it was the end of the season, we did the closing and winterization simultaneously, and it sat that way until this past weekend. The water looked pretty clear (no green) when the cover was removed. I could see the bottom of the pool and there wasn't much debris. As I was removing the return plugs, I noticed the sides of the pool had a gritty, sandpaper like feel - small crystals that come off with light rubbing, but they appear to be everywhere. I completed the opening, got the pump working, added DE to the filter and put the Polaris to work while my daughter started brushing the sides a bit (which did make things quite cloudy).

    First water test:

    Cl: 0
    pH: 8.0
    TA: 120
    CYA: 0
    Ca Hardness: 180
    Temp: 61

    I added 311 ounces of 6% bleach last night (numbers from The Pool Calculator) and retested this morning:

    Cl: 2.5

    All other readings were the same as the day before:

    The water is now very cloudy and I can only see to a depth of about 3 feet. The filter pressure rose 10 PSI overnight, so I backwashed this morning. The Polaris bag was filled with opaque crystals of some sort (see the attached photo). I emptied the bag and it was refilled again in just a few minutes.

    Any idea what this stuff is? Part of my Hydrazzo? A residue of the acid wash? Can I filter my way out of this or do I need to be thinking about another drain, clean, and refill? I haven't added any more DE to the filter yet, thinking these crystals are large enough to get caught in the untreated filter fabric. I really don't want to go through 7 pounds of DE every day until this stuff is gone.

    Thanks for any insight.

    Bob

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    Join Date
    May 2008
    Location
    Central New Jersey
    Posts
    7
    Looks like my original picture was too big, so here it is again...

    Bob
    Attached Images Attached Images

  3. Back To Top    #3
    Mod Squad JohnT's Avatar
    Join Date
    Apr 2007
    Location
    SW Indiana
    Posts
    8,618

    Re: Crystals Everywhere - Any Ideas?

    Quote Originally Posted by njbobcat23
    I haven't added any more DE to the filter yet, thinking these crystals are large enough to get caught in the untreated filter fabric. I really don't want to go through 7 pounds of DE every day until this stuff is gone.
    Bob, I can't give you any insight into the crystals, but don't run your filter without DE. Backwashing won't clear the grids if they are used to filter without DE, so you'll be forced to disassemble the filter to clean them.
    TFP Moderator
    20K Gallon 20X36 Vinyl Inground
    Hayward S244T Sand Filter with 1HP Whisperflo Pump. Liquidator C-201 and Solar Heat

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