Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 3 of 3

Thread: How to manage CSI; and calcium hardness increasing

  1. Back To Top    #1
    Sandra B's Avatar
    Join Date
    Aug 2011
    Location
    Shreveport, LA
    Posts
    103

    How to manage CSI; and calcium hardness increasing

    Hi all. I've been TFP for three years now so nothing goes in my pool except what I know. I have two questions:

    1) When I first started testing my pool in summer 2011 my CH was 170 and I raised it to 300. It's stayed around 300 (plus or minus 30) these last 3 years. Last test was 6/25/14 at CH320. Today I tested 7/21/14 and it is 400! I did the test twice. I tested my tap water and it's less than 100. Since 6/25/14 I have added MA and CYA only. I have a new salt cell so have been running on the higher side of FC (around 9-10) as I adjust my salt cell run time and % to get to an ideal of around 8. So what is making my CH rise? I know what I need to do to lower it (25% drain), but what is causing the climb? Before I drain I'll wait a few days and test again.

    2) I have calcium scale, identified by calcium deposits on the bottom and sides of the pool. I attribute this to me not paying attention to PH frequently enough during the winter . The sides I can readily clean with a stone thing (don't remember at the moment what it's called) but I can't hold my breath long enough to do the bottom. So I've been trying to manage CSI in an attempt to naturally reabsorb the calcium. BUT, I can't find any reasonable combination of chemical balance in PoolMath to get my CSI closer to zero. I usually run around -.4 to -.5. What do I need to balance to drive my CSI closer to neutral, and is this what I should be doing? The CSI for the SWG/plaster preset "goal" is -.56, so I'm not sure if that should be my goal rather than 0.

    Today's readings:

    Water temp: 83 (was in the 90's the last couple weeks)
    Salinity: 3.1
    FC: 10
    CC: .5
    TC: 10.5
    PH: 7.4
    TA: 60 (dropped from 70 after MA addition so I'm just letting it ride and watching)
    CH: 400
    CYA: 65
    Borates: 60
    CSI: -.5

    Thanks for your help!

    Sandra
    18,000 gallon freeform inground plaster
    Jandy 1.5 hp pump & .75 hp booster pump
    Aquapure SWG
    Pentair Triton II sand filter
    Legend pressure-side vacuum

  2. Back To Top    #2
    Sandra B's Avatar
    Join Date
    Aug 2011
    Location
    Shreveport, LA
    Posts
    103

    Re: How to manage CSI; and calcium hardness increasing

    Gratuitous pictures

    Calcium spot:
    calcium.jpg

    & long shot of calcium spot showing water clarity and sparkliness where not in the shade. The vacuum is 6.5 feet down.
    cleaner.jpg

    Thanks!
    18,000 gallon freeform inground plaster
    Jandy 1.5 hp pump & .75 hp booster pump
    Aquapure SWG
    Pentair Triton II sand filter
    Legend pressure-side vacuum

  3. Back To Top    #3
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: How to manage CSI; and calcium hardness increasing

    CSI in the -0.4 to -0.5 range is fine for day to day balancing. I would raise the PH a little from what you have for normal use, say to 7.7, but that isn't critical or anything.

    If you want to remove calcium scale by lowering CSI, which I don't really recommend, you would need to get CSI down below -1, and keep it there for a while. Doing that is called a no drain acid wash, and removes plaster from the pool surface as well as removing the scale. It also often takes months.
    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

Posting Permissions

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