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Thread: Here we go again - metal stains reappeared after shocking

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    Here we go again - metal stains reappeared after shocking

    This is probably going to be long but I don't know how to tell a short story.

    Backstory - we have a BBB pool. It's fantastic. Our friends have a pool too. They got fed up with terrible pool service and asked us to help them take control this year. It was incredibly rewarding to see them transform from people who didn't know anything about pool care into very hands-on owners! I posted pics in a previous thread about the before/after of their swamp into a sparkling pool. After the initial shocking process we treated some metal staining using localized vitamin C and sequestrant. Things looked great.

    THEN - after enjoying the pool for only a couple of days the you-know-what hit the fan. In a previous post I said they were battling fungus from a near by tree. NOT THE CASE. Thankfully before cutting down a huge oak tree they got a few second opinions. Not fungus but a caterpillar infestation - oak worms. Good grief its disgusting. They are all over the neighborhood (thankfully we don't have oak trees at our house!) What we originally thought was fungus was actually frass (fancy name for caterpillar poo. )

    The good news is that with some appropriate (and needed) tree trimming and just passage of time the caterpillar/frass issue is resolving.

    So here's where we are now...
    While dealing with all of the frass and caterpillars in the pool, we kept the chlorine level at the upper end of their recommended range - knowing it would be needed for all the organic matter. During the worst of the frass dropping they covered the pool with a solar cover and kept the Polaris running to pick up anything that slipped through. When they took the cover off the other day, the water was a bit cloudy so they tested and began to raise the FC to shock. After two days the water is back to clear and they passed the OLCT.


    My understanding is that they probably fell out of suspension when we raised the chlorine quickly to combat the frass. Is that a reasonable guess?

    Now that the shocking process is over they are letting the FC go back to the recommended range.

    Congratulations if you made it through all of that! Here is my main question -

    After putting in more vitamin C and sequestrant (which is so fun to do because the results are INSTANT) - we should closely monitor FC right? (we didn't drop it all the way to zero but it isn't at shock level either). I know chlorine and AA will consume each other - so we need to watch FC and make sure it doesn't drop below recommended range (to prevent algae from blooming). If it gets low and it needs to be raised, the plan is to raise it very slowly - in small increments instead of one big wallop. Small increments should prevent restaining, right?

    I know we aren't following the AA treatment to the letter but I'm scared to drop FC to zero given the fact that they have already had to go through the shock process twice since opening! I don't want to risk algae or restaining of metals.

    Good grief that was a lot of rambling. I guess I just want confirmation that our current plan is ok - maybe not perfect - but reasonable.


    p.s. Anyone know of a good website for buying sequestrant with decent shipping costs? None of the recommended ones (Jack's magic - The pink stuff or Pro Team Metal Magic) are found locally. They are using hTh Metal Control which has the recommended ingredients but in a lower concentration.
    ~35K gal, IG vinyl Grecian shape, Haywood sand filter, Polaris 380 (called "Buddy")
    located in central Arkansas
    Built in 1986 and looks better than ever!

  2. Back To Top    #2
    Mod Squad Bama Rambler's Avatar
    Join Date
    Jun 2009
    SouthWest Alabama

    Re: Here we go again - metal stains reappeared after shockin

    You also need to keep the pH down close to 7, maybe 7.2. That will help the staining too.
    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
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