Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 13 of 13

Thread: Super high calcium. How much should I drain

  1. Back To Top    #1

    Join Date
    May 2013
    Location
    Fresno, Ca
    Posts
    6

    Super high calcium. How much should I drain

    I just bought a top of the line testing kit and oh boy what a shock. Let me back up. I have a nice clear pool but getting a tiny bit of greenish/yellowish algae in the shady side that appears after about a week. Brush it and it goes away but pops up again about a week later. I tested my water and this is what I got. BTW my tap water measures 60 ppm calcium hardness. I am assuming I should drain part of the water but how much. Also I would like to stop using the solid sanitizers and switch to liquid after reading the recommendations on this forum. Any other suggestions would be appreciated. I have owned this pool for 20 years and starting to realize I don't know a heck of a lot about how to maintain it! Thanks.....Mark in Fresno

    Free clorine.............5.2
    No measurable combined clorine
    PH...........................7.6
    TA...........................110 ppm
    Calcium hardness.....625 ppm
    CYA.........................100 ppm
    12K, IG plaster 20 yrs old., 2.2 hp 2 spd. motor, 300 sq.ft. System3 cartridge filter, Hayward pool vac

  2. Back To Top    #2
    Mod Squad JohnT's Avatar
    Join Date
    Apr 2007
    Location
    SW Indiana
    Posts
    9,089

    Re: Super high calcium. How much should I drain

    Welcome to TFP!

    What is the hardness of your fill water? That can make a big difference in how much you need to replace.

    If you'll check out the Chlorine/CYA chart you'll see that your chlorine level is too low for 100ppm CYA. That may be the source of your algae issue.
    TFP Moderator
    20K Gallon 20X36 Vinyl Inground
    Hayward S244T Sand Filter with 1HP Whisperflo Pump. Liquidator C-201 and Solar Heat

  3. Back To Top    #3
    linen's Avatar
    Join Date
    Jul 2010
    Location
    Twin Cities, MN
    Posts
    8,649

    Re: Super high calcium. How much should I drain

    Welcome to tfp, Grione45

    Which kit did you get?

    Your CH is high but can be managed, however the high cya is a problem. It maybe that your cya is even higher than 100 ppm, since most cya tests are not that accurate up above 100. Assuming you are using a liquid cya test, I would repeat that test using 1/2 pool water and 1/2 cya free water (tap water is fine for this) and multiply your result by 2 to see a better approximation of where your cya is.
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

  4. Back To Top    #4

    Join Date
    May 2013
    Location
    Fresno, Ca
    Posts
    6

    Re: Super high calcium. How much should I drain

    I have the Taylor K-2006 testing kit and the calcium hardness of my fill water is 60ppm..
    12K, IG plaster 20 yrs old., 2.2 hp 2 spd. motor, 300 sq.ft. System3 cartridge filter, Hayward pool vac

  5. Back To Top    #5
    linen's Avatar
    Join Date
    Jul 2010
    Location
    Twin Cities, MN
    Posts
    8,649

    Re: Super high calcium. How much should I drain

    So it seems that you have been using Cal-hypo to chlorinate?

    What you describe sounds like mustard algae. Before proceeding with that though, you need to get the cya level (and by default this will also lower the CH level) by doing a drain refill. Perform the cya dilution test I described above and post your results so we can better know how much of a drain/refill you need.
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

  6. Back To Top    #6

    Join Date
    May 2013
    Location
    Fresno, Ca
    Posts
    6

    Re: Super high calcium. How much should I drain

    Hello there linen,
    I performed the test you suggested for the CYA and my results came out to 140, and to answer your second question I have been chlorinating with the trichlor pucks and the occasional cal-hypo shock.
    12K, IG plaster 20 yrs old., 2.2 hp 2 spd. motor, 300 sq.ft. System3 cartridge filter, Hayward pool vac

  7. Back To Top    #7
    Patrick_B's Avatar
    Join Date
    Jun 2011
    Location
    Midland TX
    Posts
    15,001

    Re: Super high calcium. How much should I drain

    Hey Grione, welcome to TFP. Linen is right about your CH, but if you get the CYA down to normal levels it will automatically correct the CH as well if you use that fill water. In the future, I would go with manual additions of bleach for your FC. It will be very easy with that size of pool.
    TFP Moderator
    Essential Links:
    ABC's Of Pool Chemistry, Test Kits, SLAM Your Pool
    28K Gal IG FreeForm, CLI Quartz, Pentair 36"SF & VS Pump, Dolphin M5, Rheem

  8. Back To Top    #8

    Join Date
    May 2013
    Location
    Fresno, Ca
    Posts
    6

    Re: Super high calcium. How much should I drain

    Thanks for the advice everyone, much appreciated. Also Brushpup, by manual additions of bleach do you mean liquid chlorine? Also hoping to hear back from Linen on how much he/she thinks I should drain.
    12K, IG plaster 20 yrs old., 2.2 hp 2 spd. motor, 300 sq.ft. System3 cartridge filter, Hayward pool vac

  9. Back To Top    #9
    linen's Avatar
    Join Date
    Jul 2010
    Location
    Twin Cities, MN
    Posts
    8,649

    Re: Super high calcium. How much should I drain

    Well since your cya is ~ 140 ppm, that means you need to drain about 64% of your water to get to 50 ppm (or recommended level). Do you know what your ground water level is? If you are uncertain, then you may want to drain about 1/3 twice and see where your cya level is then drain again to get it below 50 ppm (this will use more water). By the way linen=he
    TFP Expert who uses Pool School and my TF100 test kit along with PoolMath for my: Round 11K gallon AGP with deep end, 20" sand filter, Matrix 1hp 2spd, 6 2ftX20ft solar panels (and solar cover!), Intex SWCG (copper bars disconnected) and a Rubadub hot tub (chlorine). The SLAM process is not finished until: 1. CC < 0.5 ppm, 2. An OCLT < 1.0 ppm and, 3. The water is crystal clear.

  10. Back To Top    #10
    Patrick_B's Avatar
    Join Date
    Jun 2011
    Location
    Midland TX
    Posts
    15,001

    Re: Super high calcium. How much should I drain

    Quote Originally Posted by Grione45
    Thanks for the advice everyone, much appreciated. Also Brushpup, by manual additions of bleach do you mean liquid chlorine? Also hoping to hear back from Linen on how much he/she thinks I should drain.
    Yes I do, same thing, different name. Liquid Chlorine is Bleach is Liquid Chlorine.

    Bleach will not have the side effects that Calcium Hypochlorite or Di-Chlor/Tri-Chlor will have.
    TFP Moderator
    Essential Links:
    ABC's Of Pool Chemistry, Test Kits, SLAM Your Pool
    28K Gal IG FreeForm, CLI Quartz, Pentair 36"SF & VS Pump, Dolphin M5, Rheem

  11. Back To Top    #11

    Join Date
    May 2013
    Location
    Fresno, Ca
    Posts
    6

    Re: Super high calcium. How much should I drain

    Linen, my groundwater is 60ppm. It doesn't look like it will be physically possible to get to 50ppm. ....Mark
    12K, IG plaster 20 yrs old., 2.2 hp 2 spd. motor, 300 sq.ft. System3 cartridge filter, Hayward pool vac

  12. Back To Top    #12

    In the Industry

    duraleigh's Avatar
    Join Date
    Apr 2007
    Location
    Sebring, Florida
    Posts
    30,084

    Re: Super high calcium. How much should I drain

    Linen, my groundwater is 60ppm. It doesn't look like it will be physically possible to get to 50ppm. ....Mark
    Hi, Mark,

    You are mixing up your parameters. Linen means 50 ppm CYA. There is no CYA in groundwater so I think you are getting CYA and CH intertwined.

    To add what others have said, your CYA is a far bigger issue than your CH but draining your pool down in a series of drain/refills will solve both at the same time.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
    TFTestkits , PoolMath , Pool School

  13. Back To Top    #13
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    18,768

    Re: Super high calcium. How much should I drain

    What they said. The high CYA is a bigger problem. I have much higher CH than you, and it IS manageable, although you have less wiggle room with pH and TA when it starts approaching 800.

    I periodically use a pump to drain a few inches out of my pool and use it to water the lawn, and use the water that would have gone to the lawn to refill the pool. Same usage, it just passes through the pool first. If we ever get any decent rain, that's when it's time to seriously start replacing water. I divert one of the raingutter downspouts to my pool, using the spa as a settling basin, so I can grab as much CH and CYA free water as I can. Once the storm ends, I just set the filter to spa only and it clears it up in about twenty minutes.
    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!

Posting Permissions

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