Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 7 of 7

Thread: Fairly high CYA and Chlorine - corrosive to heater?

  1. Back To Top    #1

    Join Date
    Mar 2016
    Location
    NC
    Posts
    31

    Fairly high CYA and Chlorine - corrosive to heater?

    Our CYA is 80 and Chlorine at 9ppm, which according to the CYA/Chlorine chart is acceptable I believe. I just spoke with the pool maintenance company who did our initial water/chemicals setup (new build last summer), and mentioned to him our CYA/Chlorine levels and he kindof freaked out that the chlorine was "off the charts". He said that is way too high and is corrosive to the copper pipes in our pool heater (which we only use for the spa occasionally, but the way it is plumbed the water flows through it even when not in use). I do have a bag of bio-active that I'm planning to use to reduce the CYA once the chlorine level goes down, but he also suggested I add some type of metal-out chemical to help prevent the corrosion...I hadn't had to add anything like that before so wasn't sure what that would be. I know there are many knowledgable folks in this forum, so I was curious if you agree or disagree with the corrosion concern? I'm still learning as we haven't had the pool a full year yet. Thanks!
    15K gal, IG plaster, 2 Jandy variable speed pumps (1 for filtration and 1 for spa returns/spillover), Jandy CL Cartridge filter, Delta UV, Jandy gas heater, Rola-Chem for chlorine and acid; pool build completed June 2016

  2. Back To Top    #2
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    20,296

    Re: Fairly high CYA and Chlorine - corrosive to heater?

    Disagree completely.

    When I took over my pool, I had CYA in the 220-240 range. Hard to be more accurate than that when you're diluting 1:3 and 1:4 just to test. I couldn't drain then due to severe water restrictions, so I had to maintain FC up in the 20s. Five years later, my heater -- that has every drop of water that gets filtered run through it -- is still watertight.

    I might add that we swam in that 20 FC water with no eye irritation, no smell, and no bleached-out swimsuits. The CYA buffers the chlorine. I don't think I can explain buffering even though I understand it a little from college chemistry, but it's like buffered aspirin. You get the pain relief without tearing up your stomach.

    If you search bioactive using the search box, you'll see that the results have been somewhat underwhelming.
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

  3. Back To Top    #3

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,941

    Re: Fairly high CYA and Chlorine - corrosive to heater?

    The pool maintenance company simply does not understand the effect of CYA. This forum does and has proven it's buffering effect in thousands of pools across the US.

    Leave your CYA alone......it's OK for an SWG.......don't let it get any higher, though.

    Give that bag of bioactive to someone you really don't like. It doesn't work.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  4. Back To Top    #4

    Join Date
    Mar 2016
    Location
    NC
    Posts
    31

    Re: Fairly high CYA and Chlorine - corrosive to heater?

    Thanks for the quick responses...I think you're right that they don't understand the buffering effect of CYA...very frustrating. I don't have an SWG; would your opinion still be to leave the CYA alone in that case? That is disappointing about the bioactive...
    15K gal, IG plaster, 2 Jandy variable speed pumps (1 for filtration and 1 for spa returns/spillover), Jandy CL Cartridge filter, Delta UV, Jandy gas heater, Rola-Chem for chlorine and acid; pool build completed June 2016

  5. Back To Top    #5
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    20,296

    Re: Fairly high CYA and Chlorine - corrosive to heater?

    Quote Originally Posted by bmsm6 View Post
    Thanks for the quick responses...I think you're right that they don't understand the buffering effect of CYA...very frustrating. I don't have an SWG; would your opinion still be to leave the CYA alone in that case? That is disappointing about the bioactive...
    80 is within the recommended range for a SWG pool. Pool School - Water Balance for SWGs
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
    Troublefree does not mean Maintenancefree. It's like brushing your teeth: You can spend a couple minutes a day and pennies a week or go to the dentist once a year and spend several thousand dollars.
    A pool is like a pet - you have to feed it every day, even the days you don't want to play with it!

  6. Back To Top    #6

    Join Date
    Mar 2016
    Location
    NC
    Posts
    31

    Re: Fairly high CYA and Chlorine - corrosive to heater?

    Quote Originally Posted by Richard320 View Post
    80 is within the recommended range for a SWG pool. Pool School - Water Balance for SWGs
    Just to clarify, we do NOT have a SWG pool...
    15K gal, IG plaster, 2 Jandy variable speed pumps (1 for filtration and 1 for spa returns/spillover), Jandy CL Cartridge filter, Delta UV, Jandy gas heater, Rola-Chem for chlorine and acid; pool build completed June 2016

  7. Back To Top    #7
    JoyfulNoise's Avatar
    Join Date
    May 2015
    Location
    Tucson, AZ
    Posts
    14,075

    Re: Fairly high CYA and Chlorine - corrosive to heater?

    You can operate a manually chlorinated pool at 80ppm CYA just fine.

    What your pool guy doesn't understand is that corrosion is almost entirely dominated by pH and dissolved oxygen levels. There's very little dissolved O2 in pool water and metal corrosion (absent any type of galvanic coupling or impressed currents) typically only starts when the pH gets low, below 7. Chloride sources (salts, chlorinating liquids, etc) enhance certain forms of corrosion and will allow corrosion to occur at higher pH BUT the presence of either chloride or CYA will not initiate corrosion. These guys just simply don't understand the science behind corrosion, they attribute rust and corrosion to the wrong sources and then they spread the misinformation to either appear "smart" or to try to sell you something you don't need...
    Matt
    16k IG PebbleTec pool, 650gal spa, spillway and waterfall, 3HP IntelliFlo VS / 1.5HP WhisperFlo, Pentair QuadDE-100 filter, IC40 SWCG, MasterTemp 400k BTU/hr NG heater, KreepyKrauly suction-side cleaner Dolphin S300i robot, EasyTouch controls, city water, K-1001, K-2006 and K-1766 test kits, Mannitol test for borates

Posting Permissions

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