+ Reply to Thread
Results 1 to 2 of 2

Thread: Questions about alkalinity and scale

  1. #1
    Join Date
    Jul 2018
    Location
    California
    Posts
    2

    Cool Questions about alkalinity and scale

    I was on this forum a while back and purchased the FAS-DPD chlorine test and I also have the total poolcare dpd test kit : I have a 25,000 gallon plaster pool with a Pentair Quad D.E. filter system. Our pool is curvy on one side with an inground spa attached to pool or with the pool. We had a big party on 4th of July and we didn't get chemicals into it until yesterday....
    Our pool looked great but still has a haze in the deep end...I made the mistake and added 5 ozs of clarifier without testing my Free chlorine ( dumb test strips said chlorine was good) so now I have tested and this is what I have
    below

    FC=1.4ppm
    CC=.2
    TC=1.6
    I was going to add 3 quarts 2 cups more 10% chlorine
    ph= 7.2
    TA= 110 to 120 ( 11 drops it started to turn pink but when I walked away it was more grey, 1 more drop turned it red)
    CYA= 34 ( we have put in stabilizer tablets )
    My question is do I drop my total Alkalinity to 100? and aerate to increase my ph? or leave that for now ....
    I also wanted to figure out how to measure my CSI as we do get a white ring around our pool on the tiles.

    We do have alot of sunlight here in San Diego area so I am wanting to know what is a good cya number and a total alkalinity number for a plaster pool. Thank you Linda

  2. #2
    PoolDoc's Avatar
    PoolDoc is offline Administrator Quark Inspector PoolDoc 5 stars PoolDoc 5 stars PoolDoc 5 stars PoolDoc 5 stars PoolDoc 5 stars PoolDoc 5 stars PoolDoc 5 stars
    Join Date
    Jan 2005
    Location
    Georgia
    Posts
    11,386

    Default Re: Questions regarding total alkalinity

    1. It's common to have haze after a party (or large bather load) ESPECIALLY if chlorine is low. Raise your chlorine to > 3.0 and keep it there for a couple of days.

    2. There's nothing wrong with a TA of 120 . . . unless something else is going on. Do you have a heater or a SWCG?

    3. Alkalinity is soluble; calcium is not. What is your calcium level?

    4. CYA=34? How did you measure that? Anyhow, CYA should generally be between 30 and 90 ppm.

    IMPORTANT: chlorine levels should be SET by CYA level, and should be the HIGHER of 2 ppm OR 5% of the CYA level.

    5. Five oz of clarifier is not an issue . . . unless something else was added, too.

    6. You are in the land of bad water. White rings MIGHT be calcium. Or they might be calcium + silica + magnesium. Do this:
    + Get some nitrile gloves or kitchen gloves.
    + Get a synthetic (non-cellulose, non-natural) sponge.
    + Make 1 - 3 cups of acid solution, using 1/4 cup of dry acid per cup of water OR 1/4 cup of muriatic acid per cup of water.
    + Saturate the sponge, and then hold it against the white ring. Notice the reaction.
    + If the ring bubbles and/or is removed . . . it's probably mostly calcium. If not, it's more likely a 'Western water mineral mess' that may have to be removed physically.

    . . . but you need to know your calcium level.

+ Reply to Thread

Similar Threads

  1. total alkalinity & ph questions
    By jimcopland in forum Dealing with Alkalinity and Calcium
    Replies: 1
    Last Post: 06-14-2014, 03:01 PM
  2. Alkalinity stuck at 0...after 50 lbs. Alkalinity Increaser
    By heyaim in forum Dealing with Alkalinity and Calcium
    Replies: 3
    Last Post: 07-22-2012, 06:51 PM
  3. Scale?
    By Andrea B in forum Dealing with Alkalinity and Calcium
    Replies: 4
    Last Post: 05-29-2012, 07:33 PM
  4. scale buildup help!!
    By marmstrong in forum Pool Chemicals & Pool Water Problems
    Replies: 4
    Last Post: 05-06-2010, 03:56 PM
  5. Scale, Scale, Scale!
    By Kricket00 in forum Pool Chemicals & Pool Water Problems
    Replies: 5
    Last Post: 09-11-2006, 06:18 PM

Bookmarks

Posting Permissions

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