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Thread: What Does This Mean?

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    What Does This Mean?

    I did the Chlorine Drop Test at 8 AM this morning and got questionable readings. After adding the R-0871 powder to the test water the solution did NOT turn pink. It stayed clear. I thought maybe the R-0871 powder was old so I tried some I had recently purchased. Same results-- clear. What is going on? What is my FC? I thought I would then try to measure the CC. I added the 5 drops of R-0003 and the water turned slightly pink. Two drops of the R-0871 caused the water to turn clear. Will someone please explain these test results.

    The pool is covered with a solar blanket and has not been used in several weeks. I removed the blanket and there is no visible algae anywhere in the pool. Water temperature is 80 degrees. I last did the Chlorine drop test on 21 Sep and the FC was 7 ppm. We have had in excess of 5 inches of rain the past week.
    In-ground concrete/vinyl 21000 g, sand filter, Pentair 1 HP and 50 gpm. Pentair Legend in-pool cleaner, Nature 2 system (cartridge removed).

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    Mod Squad Bama Rambler's Avatar
    Join Date
    Jun 2009
    SouthWest Alabama

    Re: What Does This Mean?

    Sounds like you have zero FC and 1ppm CC. Even though you don't see it I'm betting you have a bloom starting. Get some chlorine in there quickly.

    Losing 7ppm in 4 days islosing less than 2ppm/day which is perfectly normal. Why did you go 4 days without checking your FC?

    Please post a full set of numbers.
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/¼hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
    Pool School ----- Pool Math ----- TF-Test Kit

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    Re: What Does This Mean?

    I thought the FC must be 0 so I went ahead and added 364 ounces of bleach. According to the pool calculator this should get me in the 8 ppm range. I will do a retest tomorrow.

    Regarding your question on why I waited 4 days without checking the FC. As I wrote, the FC was
    7 on 21 Sep and
    7 on 15 Sep and
    9 on 11 Sep.

    4 days without checking seemed ok since the solar blanket keeps the sunlight from getting directly to the water.

    A full set of numbers are not currently available. However, tomorrow morning when I do the retest I will then get FC, CC, TA, pH and cya.
    In-ground concrete/vinyl 21000 g, sand filter, Pentair 1 HP and 50 gpm. Pentair Legend in-pool cleaner, Nature 2 system (cartridge removed).

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    In the Industry

    frustratedpoolmom's Avatar
    Join Date
    May 2007
    SWSuburban Chicago, IL

    Re: What Does This Mean?

    All the rain probably introduced some organics so the chlorine was used up quicker.
    Helpful links: Pool School; CYA/Chlorine Chart
    24' round AG pool, 52" high, Raypak heater; Waterway 2 spd Pump;
    150 Sq ft. Clearwater Cartridge Filter; Former and DISSATISFIED "Pool Frog" owner
    Perfectly Clear Pool Service, Find me on Facebook!

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