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Thread: Yellow / green....stuff

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    Join Date
    Aug 2015

    Yellow / green....stuff

    I've a new account, but have been following the site and process for a couple of years. This summer, I've hit one of those.....odd kind of issues.

    I'm using bleach, occasional dry acid to keep the ph down, occasional chlorine tables in a chlorinator to keep the CYA up. I've SLAMed the pool twice so far this summer.

    The problem is that get this very fine yellow greenish powder on the bottom of the pool. It accumulates in obviously visible quantities in 2-3 days after brushing. IT doesn't clump at all, but is a perfectly fine light powder which wipes off with a hand when you lightly touch it, and dissolves immediately in the water. It also it fine enough to make it through my pool vac cloth mesh bag. Mostly on the bottom with occasional bits on the sides.

    The odd part is that there is a slight drip occasionally coming off my pressure gauge which has left a bright yellow dry residue trail down the side of my sand filter.

    Numbers are
    Chlorine 4-6
    CYA 50
    PH 7.4
    TA 110
    Calcium 170 (I need to add a bit more. Any chance this is the culprit?)

    The water is a bit cloudy and has a slightly yellow/green tinge.

    Also, the pool gets full sun and the powder/algae distribution doesn't seem to care much.

  2. Back To Top    #2
    Mod Squad kimkats's Avatar
    Join Date
    Jul 2012
    Tallahassee, FL

    Re: Yellow / green....stuff

    HI! So glad you found TFP! We can help your clear your pool.

    Where did you get your test results (I am guessing your own test kit but........I do need to make sure)?

    I really think you need to do a SLAM. You can look at my siggy below to find the link to it.

    -Gauge----I wonder if that is rust coming out of it? Mine did that also when I used a cheap gauge

    TFP Moderator 33x52 round AG 25,600 gals Sand Filter 1.5hp Pump - 2 Speed, SLAM, Pool School, Recommended Levels, Recommended Chemicals, Pool Math, Chlorine/CYA Chart, TF-100 Test Kit

  3. Back To Top    #3

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Sebring, Florida

    Re: Yellow / green....stuff

    Welcome to the forum.

    It sounds to me like you have mustard algae.

    If that's the case, you will need to SLAM the pool again. In addition to holding your FC long enough to pass the OCLT, you will need to brush the pool frequently to brush the algae off the floor and walls and get it up exposed in the chlorinated water.

    Calcium is unrelated.

    If you do an OCLT prior to your SLAM, do the evening test and then brush that dust up into the pool. I think you will find a significant chlorine loss the next AM.

    I just realized I may have thrown these abbreviations at you too quickly.

    Have you read "The ABC's of Pool Water Chemistry" up in Pool School?

    Have you read "SLAM" article in Pool School?
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

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