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Thread: Oops. Overshocked pool.

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    Oops. Overshocked pool.

    I don't think this is a major problem, but I thought I'd check.

    We just moved into a house with a new (to us) pool. When I shocked the pool after opening yesterday, I added too much chlorine. With all the chaos of moving and unpacking, I didn't stop to think that the 182 oz bottles of chlorine I used were not gallon sizes, but larger. I ended up putting in about a half gallon too much chlorine last night. This morning, the pool looks beautiful. Well, it ought to, that was more than enough chlorine to kill everything and then some. However, the chlorine level is still way high - the Taylor test kit looks for variations of yellow, and my test water was orange.

    I was going to panic, but then I thought, the chlorine is going to be degraded by the sun (and my pool gets a lot of sun exposure), so the chlorine level will go down, and it would have gone down some anyway because it killed everything and my pool is crystal clear. My CYA level is also low (30), so that will help speed up the degradation. My thought is to not worry and let it be. However, I hope I haven't potentially damaged any of the piping. I also need to backwash the DE filter, but am concerned about releasing the high chlorine water onto the ground. I turned off the pump because the of the high pressure in the DE filter (thought it isn't anywhere near the max).

    1. Should I be concerned about releasing the backwash water into the environment?

    2. Should I leave the pump off until the chlorine level goes down, or turn it back on?

    3. The pH also rose (of course), and I need to add muriatic acid. However, if the pump isn't on, the acid isn't going to circulate quickly. If the pump is off, I guess I should wait until I turn it back on before I add the acid.

    4. Is there anything else I'm missing or should do?

    Thanks!

    Kelley
    Kelleyaynn
    21,000 gallon (+ or -) in-ground plaster pool with Nautilus DE filter, 1 hp pump, and Zodiac G4 automatic vacuum.

  2. Back To Top    #2

    Join Date
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    Re: Oops. Overshocked pool.

    Run the pump.

    High chlorine normally shows a high pH but drops when the chlorine level normalizes. Save the acid for now.

    Your CYA exactly where it should be for all forms of chlorination sans a cell (they like it at about 50 to 80).

    Wait for the chlorine to come down to swimming levels before backwashing.

    Scott
    Owner of - PoolGuyNJ LLC
    Expert Pool and Spa Repairs, Renovations, and Augmentation. Helping people decide what is the right gear for meeting their needs. Expectations Set, Expectations Met, No Surprises.

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    Smykowski's Avatar
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    Re: Oops. Overshocked pool.

    Quote Originally Posted by Kelleyaynn

    1. Should I be concerned about releasing the backwash water into the environment? Don't backwash until you're 25% above clean pressure. What was clean pressure?

    2. Should I leave the pump off until the chlorine level goes down, or turn it back on? Pump should always be on while shocking

    3. The pH also rose (of course), and I need to add muriatic acid. However, if the pump isn't on, the acid isn't going to circulate quickly. If the pump is off, I guess I should wait until I turn it back on before I add the acid. See above re: pump, but ignore the pH reading until FC comes down to normal range. At high FC levels, the pH test is inaccurate

    4. Is there anything else I'm missing or should do? Do you have a test kit to measure FC accurately? What FC were you targeting? After looking at the pool calculator, an extra half gallon will only bring your FC up 1.5 ppm higher than you planned. Likely not an issue.
    33' round, 23,000 gal AG vinyl , 1HP 2spd PowerFlo Matrix downsized with 3/4HP impeller (X2), Hayward S180T 150# sand filter (X2), Hayward H250 NG heater Pool Store year 1 - $850 for 2 months; Pool Store year 2 - $440 for 2 months, TFPC year 1 - $170 for 4 months; TFPC year 2 - $95 for 4.5 months
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    JasonLion's Avatar
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    Re: Oops. Overshocked pool.

    1) Only the slightest bit, and not because of the chlorine. The chlorine dissipates very quickly and has essentially no effect. For that matter, one pool backwashing doesn't affect anything. But tens of thousands of pools can add up. But, again, this has nothing to do with chlorine.
    2) Doesn't matter.
    3) Don't adjust PH will the FC level is very high. The PH test results are probably not valid.
    4) Not really, give it half a day or a whole day and everything will be back to normal
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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    Re: Oops. Overshocked pool.

    Thanks. When I checked the pool this morning, the pressure on the filter was about 18 psi (it started clean at about 7), so I figured I needed to backwash. However, I turned the pump off, and now that it is back on, the pressure is running at about 10 psi. That's still more than 25% of the clean pressure. So I'm now a bit confused as to whether or not I should backwash.
    Kelleyaynn
    21,000 gallon (+ or -) in-ground plaster pool with Nautilus DE filter, 1 hp pump, and Zodiac G4 automatic vacuum.

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