Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 2 of 2

Thread: Potential to become corrosive to plaster

  1. Back To Top    #1

    Join Date
    Feb 2015
    Magnolia, TX

    Potential to become corrosive to plaster

    I'm playing around with PoolMath and I'm confused by the warning the CSI field gives: potentially corrosive to plaster. The thing is, I'm entering values all right out of TFP: FC 4, Ph 7.5, TA 70, CH 300, CYA 75, Salt 3000. This gives a CSI of -0.32 and the concerning message. Whats the story? I see that I can easily raise this CSI by raising the Ph but I'm concerned that a higher Ph will lead to calcium scaling on the tile.
    19k inground w/raised spa, Hayward Omnilogic, Tcell-15, Tristar 1.85hp VSP, 250MBtu heater, C4030 filter

  2. Back To Top    #2
    Mod Squad jblizzle's Avatar
    Join Date
    May 2010
    Tucson, AZ

    Re: Potential to become corrosive to plaster

    Your CSI is within the acceptable range and keeping your pH a little higher would bring the CSI closer to zero.
    One fact you seem to be missing is that calcium scaling will not occur unless the CSI is very positive.

    I will add though, that getting a ring around the tile is nearly inevitable as it is due to water evaporation leaving all the minerals on the tile. Keeping the CSI a little negative can help, but not likely to stop a ring from developing.
    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
    If you found TFP helpful and we saved you money ... Become a TFP Supporter!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts