Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 5 of 5

Thread: CH Test - Purple Question

  1. Back To Top    #1

    Join Date
    Sep 2013
    Location
    Dallas-Ft. Worth Metroplex, TX
    Posts
    810

    CH Test - Purple Question

    After 9 drops the solution turns purple (and stays purple). 10th drop turns it blue. Do I need to do the whole fading endpoint thing or is this a good indication that my CH is 250?
    14K Freeform Gunite w/60% Blue Quartz plaster, Quad DE filter, Intelliflo VS Pump + Booster for Cleaner, Aquacal Heat Pump

  2. Back To Top    #2
    Mod Squad jblizzle's Avatar
    Join Date
    May 2010
    Location
    Tucson, AZ
    Posts
    37,389

    Re: CH Test - Purple Question

    You should add drops until the color stops changing and the last drop that causes no change does not count. Did the 11th drop make it more blue?

    I think the fading end-point is only a concern if it stays purple for multiple drops.

    Of course you could always just follow the fading end point directions and see if it makes a difference.
    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!

  3. Back To Top    #3

    Join Date
    Sep 2013
    Location
    Dallas-Ft. Worth Metroplex, TX
    Posts
    810

    Re: CH Test - Purple Question

    It always eventually changes to blue. It was at 200 when the pool was first filled and I've added 4 or 5 lbs of calcium chloride (slowly over the course of a few days so I could test in between). 260 is my goal from the calc. As I added calcium chloride it went to 225 and then eventually 250. When I tested this morning it was 250 but for some odd reason it's coming up 200 now (I tested it twice). That is really weird. Maybe a bad sample of water. It's really windy out today and my pump isn't working.
    14K Freeform Gunite w/60% Blue Quartz plaster, Quad DE filter, Intelliflo VS Pump + Booster for Cleaner, Aquacal Heat Pump

  4. Back To Top    #4
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: CH Test - Purple Question

    When you get a fading end point, the test may or may not be complete at that point, so your result is either 225 or 250, and you can't say which one without doing the test and not getting purple, perhaps by following the fading end point suggestions in the extended test kit directions. That probably isn't really needed as there is only one drop of ambiguity and it wouldn't hurt to raise CH a little in any case.
    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

  5. Back To Top    #5

    Join Date
    Sep 2013
    Location
    Dallas-Ft. Worth Metroplex, TX
    Posts
    810

    Re: CH Test - Purple Question

    Thanks Jason. I'm not so concerned about the test being off by 25 pts since I'm safe in either direction. Once I get my equipment working properly I'm going to throw another few lbs of CC in there.
    14K Freeform Gunite w/60% Blue Quartz plaster, Quad DE filter, Intelliflo VS Pump + Booster for Cleaner, Aquacal Heat Pump

Posting Permissions

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