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Thread: PH level increase while "slamming" the pool?

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    Join Date
    Jun 2013
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    Michigan
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    PH level increase while "slamming" the pool?

    Hi all....

    I started the slamming process yesterday after reading the instructions and I'm a little confused.

    Yesterday, CC was 1, CYA was 40, PH was 7.2. TA was 120 (normally runs around this figure). My reason for slamming the pool is that it had a "haze" for the last week or so and the grand baby is having issues with his skin. I took the FC up to 22 (by mistake added too much) more than the level 16 as noted on the board. Filter has been running all night. The water is sparkling clear. I vacuumed the pool (had very little) and the water is so clear, it looks like when we brought the thing and filled it up!

    I tested very early this morning and the CC was 0.5, and the FC was 18. Out of habit, and before I even realized it, I tested the PH and it was 7.8.

    So,

    1st question: Should I keep an eye on that PH or is this par for the course in slamming the pool? It was at 7.2 yesterday. I did not check TA today.

    2nd question: Do I have to repeat step 1 in the slamming process when the FC gets below 16, even though it was way higher than necessary yesterday at the start process, and came down 6 overnight? Keep in mind the CC is 0.5 right now (came down 0.5) and the pool has full sun ALL day until it goes down. I suspect in this 95+ heat and sun all day that the FC will drop considerably by evening.

    3rd question: When the FC level drops to 16, and considering the PH level is higher, is it safe to swim?

    All help is truly appreciated!
    Barb
    St. Clair MI, 18,600 AG, Sand, Hayward Pro Series, Top-Mount, Model #S210T93S, 1+1/2-Horsepower Matrix Pump. Installed June-2013.

  2. Back To Top    #2

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    Re: PH level increase while "slamming" the pool?

    The pH test can falsely read higher than the true pH when the FC is high, but it is true that the pH does go higher when you add chlorinating liquid or bleach (it drops back down when the FC is used/consumed). So generally I wouldn't worry about the pH after you've started the SLAM process. The time to adjust it down is before you start elevating the FC level.

    As for the FC level itself, SLAM is shock level and maintain, so you need to maintain the higher FC level. That's a key part of the process and requires you to test the FC and add more chlorine as needed. Focus on that rather than on the pH.

    When you have met the criteria for finishing the SLAM process -- an overnight chlorine loss test showing <= 1 ppm FC loss, a Combined Chlorine (CC) level of <= 0.5 ppm, and a clear pool, then as the FC drops below the shock level, you can swim. The somewhat higher pH will not be a problem for that.
    16,000 gallon outdoor in-ground 16'x32' plaster pool; Pentair Intelliflo VF pump; Pentair IntelliTouch i9+3s control system; Jandy CL-340 square foot cartridge filter
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    Join Date
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    Michigan
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    Re: PH level increase while "slamming" the pool?

    Hi chem-geek!

    I figured but thought I would ask. I just tested, and the FC is 14 and CC is 0. I will follow the process, be a good girl and be patient! Thanks for your help!

    Barb
    St. Clair MI, 18,600 AG, Sand, Hayward Pro Series, Top-Mount, Model #S210T93S, 1+1/2-Horsepower Matrix Pump. Installed June-2013.

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    Mod Squad jblizzle's Avatar
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    Re: PH level increase while "slamming" the pool?

    1: As chem geek said, ignore the pH while in the SLAM process (or really any time the FC > 10ppm)

    2: It is a process. You have to maintain the shock level until you pass all 3 criteria to stop

    3: It is safe to swim when the FC is < shock level ... the pH does not make it unsafe, at least while it is in reasonable range. Clearly it would not be safe if the pH was << 7
    Jason, TFP Moderator
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  5. Back To Top    #5

    Re: PH level increase while "slamming" the pool?

    sorry for ignorance but what is 'slamming" a pool? thanks Dave
    13000 gallon fiberglass, cartridge filters pentair Intelliflo Variable speed Programmable Pump separate booster pump solar panels on roof

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    Mod Squad jblizzle's Avatar
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    Re: PH level increase while "slamming" the pool?

    [slam:3k7juz7w][/slam:3k7juz7w]

    Might want to take a look through the rest of Pool School as well.
    Jason, TFP Moderator
    18k IG pebblesheen pool, Hayward ProLogic P4 w/ T-15 SWG, Pentair 1HP 2-speed Superflo, Hayward 6020 DE filter
    500 sqft Heliocol solar panels, ThePoolCleaner, TF-100 test kit w/ SpeedStir
    Pool School + Test Kit + PoolMath = A TROUBLE FREE POOL
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  7. Back To Top    #7

    Re: PH level increase while "slamming" the pool?

    Thank You, I will read the article..Dave
    13000 gallon fiberglass, cartridge filters pentair Intelliflo Variable speed Programmable Pump separate booster pump solar panels on roof

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