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Thread: Ideal numbers for SW Pools??

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    Join Date
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    Ideal numbers for SW Pools??

    Anyone willing to run down the ideal numbers when testing? Sometimes I see responses that say "xyz.... is ideal for a salt water pool". Thanks!
    ~Andrea

    24,000 IG with spa and 4 ton waterfall. Equipment: Pentair 520 Clean & Clear, Pentair VS+SVRS Intelliflo, Pentair Whisperflo 2 HP, Polairis Cleaner, Intellibrites, Pentair Rainbow 320 in-line Chlorinator, Pentair Easy touch 8 wireless and spa side remote.

  2. Back To Top    #2
    some things, like CYA, depend on your system. Check your manual to find the amount. Then use Jason's calculator to find your optimal FC for a SWG.

    pH 7.2 - 7.8 (but most prefer 7.4 - 7.6)
    ch don't know!
    TA 90-120
    salt usually around 3000, again, check your manual.

    Hope this helps!

    8200 gallon 20' x 48" round vinyl frame pool, manually chlorinated with 10% liquid, salt added to ~2000, 12" sand filter, 1600gph pump, TF100 test kit
    Handy Links: PoolMath, TF-100 Test Kit, Pool School, Chlorine/CYA Chart
    "Shock" is a process, not a product!

  3. Back To Top    #3
    Guest
    For a salt pool these numbers are very good at helping prevent pH rise and maintaining a proper chorine level.
    FC 3-5 ppm
    CC < .5 ppm (If it's higher shock with liquid chlorine to about 15-20 ppm)
    pH 7.6 (when it hits 7.8 add enough acid to drop it to 7.6 and no lower)
    TA 70-90 ppm before stabilizer correction (this will help lower the amount of CO2 outgassed and help slow the eventual pH rise)
    CH 250 or so for vinyl or fiberglass, 300 for plaster. Slighly higher is OK but check your cell for scaling regularly.
    CYA 70 ppm or slightly higher unless you have one of the 'Australian style' SWGs that recommend 80-100 ppm CYA. In that case 80-90 is a better choice
    Borates 50 ppm (when they drop to 30 ppm bring them back up to 50). This will help stabiize the pH and reduce acid consumption and sanitizer demand.

    I have seen these numbers work on my own pool and my customers pools. The most important numbers are the FC, pH, TA, and CYA. Borates do make a big difference. I would definately recommend them. Calcium is more important for plaster pools. You want the calcium saturation index to be on the slightly scaling side. In a fiberglass or vinyl pool slightly aggresive to slightly scaling is ok. Actually pH is the most important thing to watch for scaling or agressive water and temp the second most imortant. If your calcium is in the ballpark then don't worry about it too much. If it is very low or very high then it can be problematic.

  4. Back To Top    #4

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    Quote Originally Posted by waterbear
    For a salt pool these numbers are very good at helping prevent pH rise and maintaining a proper chorine level.
    FC 3-5 ppm
    CC < .5 ppm (If it's higher shock with liquid chlorine to about 15-20 ppm)
    pH 7.6 (when it hits 7.8 add enough acid to drop it to 7.6 and no lower)
    TA 70-90 ppm before stabilizer correction (this will help lower the amount of CO2 outgassed and help slow the eventual pH rise)
    CH 250 or so for vinyl or fiberglass, 300 for plaster. Slighly higher is OK but check your cell for scaling regularly.
    CYA 70 ppm or slightly higher unless you have one of the 'Australian style' SWGs that recommend 80-100 ppm CYA. In that case 80-90 is a better choice
    Borates 50 ppm (when they drop to 30 ppm bring them back up to 50). This will help stabiize the pH and reduce acid consumption and sanitizer demand.

    I have seen these numbers work on my own pool and my customers pools. The most important numbers are the FC, pH, TA, and CYA. Borates do make a big difference. I would definately recommend them. Calcium is more important for plaster pools. You want the calcium saturation index to be on the slightly scaling side. In a fiberglass or vinyl pool slightly aggresive to slightly scaling is ok. Actually pH is the most important thing to watch for scaling or agressive water and temp the second most imortant. If your calcium is in the ballpark then don't worry about it too much. If it is very low or very high then it can be problematic.
    I've been closing in on these numbers, but I have a question about CSI and my plaster pool. When I plug these numbers into the Pool Calculator, I get a CSI of -0.14 at 85 degrees temperature. Since the recommendation is to have the CSI slightly above 0.0 with a plaster pool, how should I adjust the targets to achieve this CSI?

    Also, how do I test for borates?
    blubluenoiseise

    My pool: 14,750 gallons in-ground plaster
    FAFCO Solar panels (seven 4' x 12') with a Goldline automatic controller
    1/2 HP WhisperFlo filter pump, Kreepy Krauly cleaner, Cartridge Filter
    Aquarite SWG, Satisfied user of the TF-100 Test Kit

  5. Back To Top    #5
    JasonLion's Avatar
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    I would balance the CSI by raising CH.

    There are test strips for borates that seem to be good enough, AquaChek I believe. LaMotte also makes test strips that are better, but they appear to be difficult to find.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  6. Back To Top    #6

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    Quote Originally Posted by JasonLion
    I would balance the CSI by raising CH.

    There are test strips for borates that seem to be good enough, AquaChek I believe. LaMotte also makes test strips that are better, but they appear to be difficult to find.
    All else being equal, it appears I'd need to put the CH at 410 to get to 0.01 on the CSI. Is that going to cause scaling problems for my SWG's cell?
    blubluenoiseise

    My pool: 14,750 gallons in-ground plaster
    FAFCO Solar panels (seven 4' x 12') with a Goldline automatic controller
    1/2 HP WhisperFlo filter pump, Kreepy Krauly cleaner, Cartridge Filter
    Aquarite SWG, Satisfied user of the TF-100 Test Kit

  7. Back To Top    #7
    Guest
    CSI is only a guide. I would not lose sleep over a -.14 CSI. pH is the main factor that will change CSI with temp the second factor. Unless the numbers are REALLY out of whack you are fine! IMHO, a slightly agressive number such as you have will help prevent scaling of the cell. People get too hung up on saturation index numbers. IT IS ONLY A GUIDE and not really much more useful than a TDS reading, IMHO.

  8. Back To Top    #8

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    Thanks yet again, folks, for the great info!
    blubluenoiseise

    My pool: 14,750 gallons in-ground plaster
    FAFCO Solar panels (seven 4' x 12') with a Goldline automatic controller
    1/2 HP WhisperFlo filter pump, Kreepy Krauly cleaner, Cartridge Filter
    Aquarite SWG, Satisfied user of the TF-100 Test Kit

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