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Thread: Do you really need CYA?

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    Do you really need CYA?

    I have a fiberglass pool with an automatic safety cover; the pool is primarily kept closed as a safety issue to keep my kids, particularly my son who has autism, away from the danger of drowning. We've had the pool for 4 years now, but just recently discovered your sight! The bane of my existence has been trying to lower my alkalinity which has been around 220+ PPM for years now - I would add the acid, it would go down along with the PH, I would add borax or ph up and the alkality would go up again - a complete nightmare. My local water in Poolesville, MD is very high in TA, usually at 230 PPM. I gave up last year and stopped testing for it, and would only make sure my FC and Ph were good. Your site showed me how to use the Muriatic acid and then boost the pH with the aeration (which I did by closing off one of my returns and pointing the other one straight up). Thanx to you I'm now holding steady at 100 PPM.

    I've never understood what CC was until I started to read this site, and then realized that my CC was around 5 PPM about a week ago! That would probably explain some eye irritation and funky smell when the cover comes off all last year, and now this year! For the past week I have been lowering the TA with the acid and left the pool uncovered for several days while I treated it. For whatever reason, the FC then increased by itself to 2 to 4 ppm, then 5 ppm and is now at 2 ppm. During these same several days my CC has dropped from 5 ppm to now 2 ppm. Do you guys know how that happened even though I never added any chlorine?

    That brings me to the CYA issue. No one has ever told me to use CYA, and I've never added or tested for it. Over the years the pool has been crystal clear most of the time, with an occasional hiccup that I could solve by a bag of burnout. The swimming experiences over the past several years have been wonderful, although I think the high CC issue has always been there, I just didn't understand it until I found you folks.

    I have the high end Taylor test kit and ran my numbers today:

    FC .5
    TC 2.5
    CC 2.0
    CH 240
    TA 100
    pH 7.3
    CYA is negligible. I poured the cloudy solution in the test vial and filled it completely up -- I could clearly see the black dot although the solution was a bit cloudy.

    I'm trying to follow the BBB now, so to burn out the CC of 2.0 I added 3.5 gallons of liquid chlorine tonight and will keep the pool open for several days as it does its work.

    So, here is my question. Once I get this CC out of the picture, do I need to add CYA if I'm going to use the BBB method and the pool remains covered most of the week? I have yet to find any forums or even the folks at my Leslies or Contemporary Watercrafters (local pool store) who seem to understand what covering the pool most of the time does to the chemistry.

    San Juan Luxor Deep Fiberglass
    22,000
    Sta-Rite System 3 Cartridge Filter
    Polaris 280
    Sta-Rite 3/4 hp Pump Running 24/7 for right now till I figure out the BBB Method - not sure about the flow rate.
    I'm keeping the pool frog mineral pack in, but will try and use BBB and forget the BacPacs of chlorine.

    PS - my son is 7 and an absolute self taught fish! Dives to the bottom of the deep end, and just loves the water! My daughter, 9, also loves to swim...
    San Juan Luxor Deep Fiberglass
    22,000 Gallons
    Pool Frog
    Sta-Rite System 3 Cartridge Filter
    Sta-Rite 3/4 HP Pump
    CoverStar Automatic Safety Cover

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    JasonLion's Avatar
    Join Date
    May 2007
    Location
    Silver Spring, MD
    Posts
    37,879

    Re: Do you really need CYA?

    I recommend keeping CYA around 30. We recommend keeping CYA between 20 and 30 for indoor pools. High FC levels without any CYA can cause equipment damage. Zero CYA also promotes the creation of some of the nastier forms of CC. You will also have the pool open to the sun at least occasionally, and a little CYA will dramatically reduce the amount of FC lost to sunlight at those times.

    With an automatic cover, I recommend keeping the cover open at least a couple of hours a week. Often you will be swimming enough to take care of this. Sunlight helps break down CC and some of the slower chemical processes that we don't normally worry about require exposure to the open air.
    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: Do you really need CYA?

    I just added the liquid chlorine tonite, and I'm not sure how much CYA to add since I can't get any kind of a reading its so low. I just used the calculator to take it from 10 to 20 just to be on the safe side and it said 1 lb 13 oz - I do have some stabilizer, is it OK to add that tonight or tomorrow AM just after I super shocked?
    San Juan Luxor Deep Fiberglass
    22,000 Gallons
    Pool Frog
    Sta-Rite System 3 Cartridge Filter
    Sta-Rite 3/4 HP Pump
    CoverStar Automatic Safety Cover

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

    Re: Do you really need CYA?

    You can add the CYA any time, just leave the pump running for 24 hours afterwards.
    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
    Mar 2008
    Location
    Los Angeles, Ca
    Posts
    218

    Re: Do you really need CYA?

    I have a manual safety cover, and am going to have about 20-25 ppm cya. Right now, it's less then 15, ran out, and had to buy some more, and haven't got around to adding it yet.

    I had none when I opened the pool, so if the kids swim all day, most of the fc would be gone by the end of the day.

    Chemgeek (Richard) is VERY knowledgable on pool chemistry, and I know he has a automatic safety cover, and keeps some cya in his pool. He has a technical explanation about how the cya combines with chlorine, to make it less irritating to your clothes/body, but holds the chlorine in reserve for when you need it.

    Randy
    25,000 gal fiberglass pool, Raypak 200k BTU H200FDN gas heater, Pentair CCP520 520 sq ft Cart filter, Max-Flo VS2303VSP pump. iWave wireless remote,

    seperate spa, with own pump, cartridge filter, Hayward H200FDN heater

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