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Thread: Checking Sequestrant ppm in areas of high wind blown iron

  1. Back To Top    #1

    Join Date
    Aug 2008

    Checking Sequestrant ppm in areas of high wind blown iron

    Where we live in Honolulu up a mountain at about 1000 ft, the mountains behind us reach about 2,500 ft high, the winds normally blow at 16 to 24 mph. On some rare days the winds blow up to 60 mph, average though on those high wind days is 45 to 55 mph. I believe but do not know for sure that some parts of the US mainland, maybe some parts of Texas have the same issues with wind.

    The wind carries what we call call "Red Dirt" or volcanic dust that contains iron. A few years ago I use to add sequestrant at about 5 oz a week without a kit to check the level in the pool. I now use a kit from Jack's Magic to check the level of Purple Stuff in our SWG pool. Jack's Magic recommends a level of 10 to 12 ppm for maintenance, and 18 to 20 ppm for cleaning. I now maintain a level of 20, wheras before I used a level of 12, for the sake of insurance. This change and checking after high wind days has made a big difference in the length of time I now have to do the AA treatment. The reason being that on a very windy day if I check in the evening the level of sequestrant drops from 20 ppm to 10 ppm, and the pool gets topped up. On rare weeks where we have little to no wind it uses virtually no sequestrant, on normal 16 to 24 mph weeks it uses about 3 to 5 ppm of sequestrant.

    In other words if you have a high wind born iron issue the check kit is worth having.

    Keeping the pH at 7.4 or below as often mentioned on this forum is also absolutely required, I use to keep it at 7.5 and that created issues.

    Also check you filter pressure, in our case we have to backwash every two to three weeks, more often than is usually recommended, dependant on the winds, or the pool steps start to get the yellow/brown tinge. Adding some lighly ground Vitamin C tablets (not to powder or it floats away) from WalMart, the cheapest I found in Honolulu, helps remove these slight stains if the pump is turned off. You might need to check your chlorine after you do this.

    I mention this for what it is worth from personal experience.
    10,000 gal plaster pool,3/4 hp WhisperFlo pump, Sta-Rite Great White GW9500 pool cleaner, Hayward 300 lb Sand Filter
    Use Magenta Stuff for Iron and Silica control.
    Balance: pH 7.7 Cl 7 -8 Alk 70-80 CH 325 CyA 30 in winter - 50 in summer NaCl 1010 TDS 1200

  2. Back To Top    #2

    Re: Checking Sequestrant ppm in areas of high wind blown iro

    Thanks for posting this. I am in the process of trying to sequester iron. I am at the point where 10-12 ppm of Jack's Purple is not cutting it. Your post gives me a bit of hope that going up in concentration will work.

    Thx again
    ~18.5K gallon plaster - two level / spa to pool waterfall
    Pentair WhisperFlo WFE-28 Pump, Pentair Clean and Clear Filter
    Hayward Pool Vac Ultra Cleaner

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