Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 8 of 8

Thread: Replacing water due to high CYA

  1. Back To Top    #1

    Replacing water due to high CYA

    I am presently alternating draining/filling to get my pool to a good cya level. So far this season my readings have continued to be higher than the TF100 test tube reads despite the fact that my pool store says my cya is 50 ppm. Unfortunately i have spent the last few weeks tackling pH and TA issues and now am afraid everything has to start over.

    I'm also sure i will lose my 50 ppm Borate level and will have to start that over as well. So now for the questions....

    When do i know when to stop draining/refilling? The calculator suggested i drain 60% of my water and i can guestimate that i suppose. From there should i just run the filter for a day or two and then test? Do i need to shock since there is new water? I really hate to have to start putting more acid, bleach, borax in and then find out i need more draining.

    Maybe the choice is clear....run everything for a few days and then start testing??
    10,000 gallon
    Viking Freeform Fiberglass Inground Pool. FNS Plus DE Filter Pentair Challenger .75hp pump

    NC KANSAS44

  2. Back To Top    #2
    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,887

    Re: Replacing water due to high CYA

    You only need to run the pump for a couple of hours after adding fresh water before you can test levels.

    Figuring out 60% water replacement does require some guessing.

    You won't need to shock as long as the FC level doesn't fall to zero.
    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

  3. Back To Top    #3

    Re: Replacing water due to high CYA

    Quote Originally Posted by JasonLion
    You only need to run the pump for a couple of hours after adding fresh water before you can test levels.

    Figuring out 60% water replacement does require some guessing.

    You won't need to shock as long as the FC level doesn't fall to zero.
    My well puts out 20 gallons per minute. So it seems to me that to add 5400 gallons which the calculator said needed to be replaced, it would take 270 minutes. I guess that is as good a guess as any.
    10,000 gallon
    Viking Freeform Fiberglass Inground Pool. FNS Plus DE Filter Pentair Challenger .75hp pump

    NC KANSAS44

  4. Back To Top    #4

    Re: Replacing water due to high CYA

    Well based on my estimates I drained around 5000 gallons of water and replenished. I ran the filter for an hour and retested. Initial results aren't impressive.

    FC 5.5
    TC 5
    CC 0
    pH 6.8
    TA 330
    CYA 80-100 depending on where i hold the test tube. Somewhat subjective...."is that the dot, yeah i think it is....er maybe not."

    I will let things run a bit and then retest but my initial concern is how to I get my TA back down without lowering my pH even further? I still need to test for borates also.
    10,000 gallon
    Viking Freeform Fiberglass Inground Pool. FNS Plus DE Filter Pentair Challenger .75hp pump

    NC KANSAS44

  5. Back To Top    #5
    frustratedpoolmom's Avatar
    Join Date
    May 2007
    Location
    SWSuburban Chicago, IL
    Posts
    11,963

    Re: Replacing water due to high CYA

    areate first then begin the acid additions. For the TA test, are you wiping the tip of the dropper bottle in between drops with a damp cloth?

    Can you do another partial drain and refill to lower the CYA a bit more...?
    Helpful links: Pool School; CYA/Chlorine Chart
    24' round AG pool, 52" high, Raypak heater; Waterway 2 spd Pump;
    150 Sq ft. Clearwater Cartridge Filter; Former and DISSATISFIED "Pool Frog" owner
    http://www.PerfectlyClearPoolService.com

  6. Back To Top    #6

    Re: Replacing water due to high CYA

    Quote Originally Posted by frustratedpoolmom
    For the TA test, are you wiping the tip of the dropper bottle in between drops with a damp cloth?
    NO. What does this accomplish?
    10,000 gallon
    Viking Freeform Fiberglass Inground Pool. FNS Plus DE Filter Pentair Challenger .75hp pump

    NC KANSAS44

  7. Back To Top    #7
    frustratedpoolmom's Avatar
    Join Date
    May 2007
    Location
    SWSuburban Chicago, IL
    Posts
    11,963

    Re: Replacing water due to high CYA

    There are verified reports that static electricity causes the drops for the TA test to come out in irregular sized drops - causing the TA results to read higher than they really are - if you wipe the tip of the R-009 in between drops it should change your result.
    Helpful links: Pool School; CYA/Chlorine Chart
    24' round AG pool, 52" high, Raypak heater; Waterway 2 spd Pump;
    150 Sq ft. Clearwater Cartridge Filter; Former and DISSATISFIED "Pool Frog" owner
    http://www.PerfectlyClearPoolService.com

  8. Back To Top    #8

    Re: Replacing water due to high CYA

    Quote Originally Posted by frustratedpoolmom
    There are verified reports that static electricity causes the drops for the TA test to come out in irregular sized drops - causing the TA results to read higher than they really are - if you wipe the tip of the R-009 in between drops it should change your result.
    Thanks. Upon retesting using that method it did give me a different reading of 220. And the drops were visibly larger.
    10,000 gallon
    Viking Freeform Fiberglass Inground Pool. FNS Plus DE Filter Pentair Challenger .75hp pump

    NC KANSAS44

Posting Permissions

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