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Thread: High CYA & CH Readings

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    High CYA & CH Readings

    I'm new to the BBB method. Recently bought a TF-100 test kit. After testing a few times I do have some questions on what to do. I'm also using the pool calculator.

    My pool is 16,000 gallons.

    My Calcium Hardness measures at 850 versus a suggested level of 250-350. To lower the level the calculator suggests I replace 59% of the water.

    My Cyanuric Acid measures at more than 100 on the TF-100 kit. The water doesn't even reach the bottom line for 100. When I plug 100 into the calculator, it tells me to replace 60% of the water.

    Is there anything else I can do for these items? Or can I just not worry about them? I know we have hard water here which is probably driving the calcium hardness number. There's just no way I can see draining half my pool and filling it with new water.

    Also, my total alkalinity is high too; measures 250 versus a target of 70 - 90+.

    Anyway, any helpful advice is appreciated.

    Thanks.

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    Re: High CYA & CH Readings

    Would you post a complete set of test results, please?

    Tell us what your water looks like.
    Dave S.
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    Re: High CYA & CH Readings

    The just about the only way you can lower those numbers is to replace the water. The other option is a reverse osmosis treatment on the whole pool and that is a long shot at best. There are only a handful of companies in the US that do reverse osmosis treatments on pools, and usually it is cheaper just to drain and replace the water.

    Your CYA is probably much higher than 100. Pools with over 100ppm are very difficult to manage. They have a very high daily chlorine demand which can be expensive over time. If you have an algae bloom it is very difficult to clear it with high CYA. To get a better estimate of your CYA level mix 1 part pool water with 1 part tap water and run the test again, doubling the result.

    The high calcium can be managed if you keep the pH in the 7.2-7.5 range and the TA in the 70-90 range. Do not use any calcium hypochlorite products in the pool as that will just add to the calcium problem. Use liquid chlorine, either from the pool store or 8% plain, unscented bleach from the grocery store to prevent adding to your CYA and Calcium problem.
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    Re: High CYA & CH Readings

    Quote Originally Posted by duraleigh
    Would you post a complete set of test results, please?

    Tell us what your water looks like.
    Total Chlorine: 4 PPM
    PH: 7.5
    TA: 250
    CH: 850
    CYA: 100
    CSI: 0.83
    Pool temp: 87 degrees F

    The pool water looks great. Crystal clear. No algae problems.

    I do have calcium scaling problems on by pool tiles. Every year I use acid and a lot of elbow grease to scrub them shiny again. Should mention that the pool is 8 years old and I've always used the 3" chlorine pucks. I'm switching to BBB, but I still have a puck in my floating chlorinator (will be gone in a week) and a couple in my automatic chlorinator.

    I run my pool pump for 14 hours on low speed (1725 RPM).

    Thanks.

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    Re: High CYA & CH Readings

    The pucks are why your CYA is so high. Your CH is high probably because of using Cal-hypo to shock.

    Continued use of those will continue to drive both numbers up and you are already out of acceptable limits.
    There's just no way I can see draining half my pool and filling it with new water.
    That will have to be your call but there is no other way to fix your pool water chemistry and things will only get worse.

    EDIT: I mistook this thread with another who reported fill water of 100 ppm CH. Please disregard my reference to Cal-hypo......it would be very helpful to know the CH of your fill water.
    Dave S.
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    Re: High CYA & CH Readings

    Sounds like you have over 100 CYA and still rising since you still have pucks in. Your chlorine level is far too low, it should be over 10 if your CYA is over 100. I'm glad your water is crystal clear, I hope it stays that way, but if you do get an outbreak then you are going to have to add insane amounts of chlorine to SLAM.

    You need to do another CYA test where you mix half tap water and half pool water and then add the reagent. Get the test results and then double it to figure out your actual CYA level. 60% may be a low estimate on how much you have to change...

    Your water is pretty warm, it would be a good idea to get your chlorine level up right away to prevent the clear water from getting cloudy. A water change would help your CYA and CH. If you can get low CH water trucked in you can get your CYA under control and save a lot of elbow grease every year. I personally would call that a worthwhile expense. However, that change will only last as long as you stop using pucks or cal-hypo shock on a regular basis.
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    Re: High CYA & CH Readings

    Quote Originally Posted by duraleigh
    The pucks are why your CYA is so high. Your CH is high probably because of using Cal-hypo to shock.

    Continued use of those will continue to drive both numbers up and you are already out of acceptable limits.
    There's just no way I can see draining half my pool and filling it with new water.
    That will have to be your call but there is no other way to fix your pool water chemistry and things will only get worse.
    I've now stopped using the pucks. Over time the water will get replaced just due to evaporation here in Texas this time of year. I know if I turn off my auto fill, the pool loses about 1" of water a day if not covered. I haven't figured out how much water that is or how long it would take to replace 60% of the water. So while it will take longer, isn't this an option instead of actually draining the pool and replacing the water?

    Thanks.

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    Re: High CYA & CH Readings

    isn't this an option instead of actually draining the pool and replacing the water?
    No. The water evaporates but the CYA remains behind. Evaporation has no affect on CYA level.
    Dave S.
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    Re: High CYA & CH Readings

    Joe,
    I'm in North Texas and had the same CYA and CH numbers as you. I've had to do the drain and refill recently and have switched 100% from the tablets and shock to strictly liquid bleach per the BBB method. We have hard water as well but after testing the fill water it was really not as high as I thought it would be. It is absolutely worth doing a drain and refill. It will save you so much money in product and save a ton of time and headaches over the long run. I was at the point of keeping my chlorine over 10ppm to keep from greening up the edges of the pool not to mention the daily chlorine usage was out of control and costing a small fortune. It is soooo much easier to maintain now it's almost funny. Best of luck!

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    Re: High CYA & CH Readings

    Quote Originally Posted by smac22
    Joe,
    I'm in North Texas and had the same CYA and CH numbers as you. I've had to do the drain and refill recently and have switched 100% from the tablets and shock to strictly liquid bleach per the BBB method. We have hard water as well but after testing the fill water it was really not as high as I thought it would be. It is absolutely worth doing a drain and refill. It will save you so much money in product and save a ton of time and headaches over the long run. I was at the point of keeping my chlorine over 10ppm to keep from greening up the edges of the pool not to mention the daily chlorine usage was out of control and costing a small fortune. It is soooo much easier to maintain now it's almost funny. Best of luck!
    Thanks for the information. Nice to hear others with similar issues and what they did. Surprisingly I'm not using a ton of chlorine and never have, yet I still have clean water. Of course I'm in the desert so I don't have all the contaminants that others may have.

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    Re: High CYA & CH Readings

    Quote Originally Posted by duraleigh
    isn't this an option instead of actually draining the pool and replacing the water?
    No. The water evaporates but the CYA remains behind. Evaporation has no affect on CYA level.
    Guess I was assuming it went away with evaporation, but it definitely makes sense that it doesn't. Thanks.

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