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Thread: Do I really need to replace 50% of my water?

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    Do I really need to replace 50% of my water?

    First post, so be gentle. Quick backstory. For 5 years I've been doing the bring a sample to the pool store every week thing, so this summer I wanted to make it easy and just have someone take care of it for me. I didn't mind the weekly balancing expense so much, but when I found out that everyone required me to do $75-$100 "filter cleanings" I couldn't take it. Too easy of a job to require so much money and it wasn't optional. Anyway, did some research and wound up here.

    I bought a Taylor K-2006 and while I was waiting on it, I assumed I had zero chlorine because I usually do, and proceeded to dump bleach in to get rid of Algae. Brush, bleach, brush bleach.

    Pools is clearer now than it has ever been, but here are my first-test numbers. I was plenty OCD about doing the test, so I trust the nubers per the directions.

    Water Temp = 71 degrees
    Air temp = 81 degrees
    pH = 7.8
    FC = 12
    CC = 0
    TA = 130
    CH = 630 (YIKES)
    CYA = 120 (or more, black dot disappeared quickly)

    The water looks great, so I'm hesitant to go drastic. Thoughts?
    ~21,000 Gallon Kidney Shaped Plaster Pool
    2 feet shallow to 8 ft deep end
    Only one skimmer, and two return jets plus Polaris 280 Jet
    Dallas, TX - West Side of House = HOT
    48 SqFt DE Filter

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    Azgirl71's Avatar
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    Re: Do I really need to replace 50% of my water?

    CYA is pretty high. You may want to consider lowering a bit. Maybe drain 1/3 and refill. You will lose some to slash out and backwashing.

    I am not sure what to tell you on the CH as I don't have a plaster pool.
    Lisa
    Intex AG vinyl 15' x 48" 4,300 gallons due to skimmer install, Krystal Clear SF pump combo 2800 GPH, Krystal Clear SWG, Pool Blaster Max vacuum, Hayward thru the wall skimmer, TF 100 test kit with speed stir, K 1766 Taylor salt test, My SLAM Process

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    Mod Squad tim5055's Avatar
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    Re: Do I really need to replace 50% of my water?

    With CYA 100+ I'm sure all the algae isn't dead yet and just waiting to spring back. A 50% water change would put up you at 60 IF the 120 is correct. 100 is the limit of the test, so anything above that is just a guess.

    I would say at least 33% at first, but you are probably looking at 50% + to get it where you really need it.

    Or, if you can just get it below 100 to,have a true reading you could SLAM it but the cost of chlorine would be massive and water exchange would probably be less expensive.

    As to the CH, I'm betting you have high CH fill water. As water evaporates form the pool the CH stays behind. You add water, and thus the CH keeps going up. Test your fill water to see what it is.
    TFP Moderator 39 X 18 23,000(ish) freeform gunite; built 2007ish; Pentair Triton II TR100 600lb Sand filter; 2 HP Pentair pump with 2.2 HP AO Smith single speed motor; 2 skimmers, 1 main drain, 4 returns w/waterfall, Stenner 45MHP2 3GPD running@ 60% - 15 gal Tank; heated by the sun CYA 200+ when I started - 50 now. Dolphin Supreme M5 Pool Cleaner. Hot Springs SX Spa, 285 gallon

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    Richard320's Avatar
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    Re: Do I really need to replace 50% of my water?

    Welcome back

    +1 on taking control with your own test kit.

    Your numbers look waaaay better than mine did when I took over my pool. However, I had no algae. My CYA was over 200. My CH has only been below 500 once in the last 3 or 4 years, after a massive rain.

    From firsthand experience I can say that you can maintain a pool with superhigh CYA, but I don't recommend it. First, repeat the CYA test using the dilution method in Extended Directions. Then you'll have a better idea how much water needs replacing. Getting rid of the algae for once and for all will be so much easier with a realistic CYA number. If you're not under water restrictions, do it. Municipal water is cheap. They usually price it in CCF - that's a hundred cubic feet, 748 gallons. Just the amount of bleach you won't need to buy for the initial shock dose at your elevated CYA will probably cancel the expense.
    Stick with the methods we preach and get your numbers in line and you will end up with a clear sparkling pool that will be the envy of the neighborhood. Seriously. Guests will actually remark on how clear the water is. My wife's best friend's kids have become pool snobs after swimming in my pool.
    16K freeform gunite with spa; Pentair 4000 DE filter; Century Whisperflow 1 HP; Pentair Minimax heater.
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    Re: Do I really need to replace 50% of my water?

    With CYA that high you need to maintain your FC between 10-15. That is quite high. Partial water replacement would also bring down your CH to a manageable level.

    I'm guessing that you used to buy Cal-hypo from the pool store for shocking the pool? Sticking with bleach moving forward since it does not add any CYA nor CH.

    I'd drain at least 1/2 and refill.
    Gary
    21k gal SW, IG Gunite PebbleSheen, 1HP Jandy, Jandy 340 filter, Polaris 280, 17' fiberglass slide w/ 2HP pump.

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    Mod Squad YippeeSkippy's Avatar
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    Re: Do I really need to replace 50% of my water?

    I would suggest keeping your pH at the lower end more towards 7.2-7.4 to help avoid scaling due to the high calcium. Because you have a plaster pool you *need* more calcium than any other pool type. If you replace some water to lower the CYA, your new fill water ought to be a bit lower. All those little water replacements with lower fill will help slowly. Just for grins, how about testing your fill water for a baseline?
    My Amazon Smile for November12K Fiberglass IG, Infinity 4000 automatic cover, SWCG, Hayward Sand Filter, Hayward 1.5 Pump, Doheny Discovery Robot, Savi Melody LED pool lights, outdoor speakers and other assorted doo-dads. Sundance Altamar Hot Tub.
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    Mod Squad pooldv's Avatar
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    Re: Do I really need to replace 50% of my water?

    Welcome to TFP!

    Order a TF100 test kit from tftestkits.net.

    Here are some intro Pool School articles to read while you are waiting for your test kit.
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    ABC's of Pool Water Chemistry

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    Re: Do I really need to replace 50% of my water?

    Poolldv, he has the K-2006 test kit so there isn't a need for the TF-100 test kit.

    DallasSocFan, if you want the pool to be simpler to take care of, you need to drain some water. I'm guessing at least 50% because you want the CYA to be around 50. This will lower the CYA and CH which will make managing the pool much simpler.
    16k gal plaster with raised spa, Jandy DEV60 filter, 2 HP 2-speed SHPF Jandy Stealth pump
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    Re: Do I really need to replace 50% of my water?

    After heavy rain last night and two quarts of acid yesterday morning and 90 ounces of 8.25 bleach last night:

    Ph 7.5
    FC 13
    CYA 95

    I didn't test the other stuff. I want to get the basics right first.

    Question: What does "just disappears" mean on the Taylor CYA test? Completely invisible, or so faded you have to strain to see it?

    I'm going to harbor freight this afternoon to get a pump to do some draining.

    Should I go for a half drain all at once or do a couple of feet, fill, and retest. I can be patient about this and want to do it right.



    ~21,000 Gallon Kidney Shaped Plaster Pool
    2 feet shallow to 8 ft deep end
    Only one skimmer, and two return jets plus Polaris 280 Jet
    Dallas, TX - West Side of House = HOT
    48 SqFt DE Filter

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    Mod Squad YippeeSkippy's Avatar
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    Re: Do I really need to replace 50% of my water?

    Doing a partial drain-->refill-->drain again, while time consuming and perhaps more costly is the safest way if you're in the least bit unsure of a liner or pool plaster not being wet.
    Others have done half drained pools without problems too. What's your comfort level?
    My Amazon Smile for November12K Fiberglass IG, Infinity 4000 automatic cover, SWCG, Hayward Sand Filter, Hayward 1.5 Pump, Doheny Discovery Robot, Savi Melody LED pool lights, outdoor speakers and other assorted doo-dads. Sundance Altamar Hot Tub.
    Our pool build--> Our Pool Solved Our Sloping Yard Skippy's Cheap Pool Cooler -->Skippy's New Fountain

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    Re: Do I really need to replace 50% of my water?

    These are the numbers for my Dallas city TAP WATER.

    Ph 8.2 (scale goes to 8. It's a touch darker)
    TA 40
    FC 0.4
    CC 2.8
    CH 70

    Looks like I'll need acid on refill.


    ~21,000 Gallon Kidney Shaped Plaster Pool
    2 feet shallow to 8 ft deep end
    Only one skimmer, and two return jets plus Polaris 280 Jet
    Dallas, TX - West Side of House = HOT
    48 SqFt DE Filter

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    Re: Do I really need to replace 50% of my water?

    I'm fine with draining halfway at once. I was just wondering.


    ~21,000 Gallon Kidney Shaped Plaster Pool
    2 feet shallow to 8 ft deep end
    Only one skimmer, and two return jets plus Polaris 280 Jet
    Dallas, TX - West Side of House = HOT
    48 SqFt DE Filter

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    Isaac-1's Avatar
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    Re: Do I really need to replace 50% of my water?

    Looks like Dallas is yet another city that has went the cheap route and is using Chloromines for sanitizing.
    Indoor 20x40 35,000 gallon vinyl pool with 1.5 HP 2 speed Jandy FloPro pump, Hayward EC75 Perflex DE filter, 11 4x12 Techno-Solis solar panels w/ Aquasolar controller, Aquabot Turbo T Robot Cleaner. Also LMI metering chlorine dispenser pump and HotSpring Jetsetter
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    Mod Squad tim5055's Avatar
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    Re: Do I really need to replace 50% of my water?

    Quote Originally Posted by DallasSocFan View Post
    I'm fine with draining halfway at once. I was just wondering.


    Sent from my iPhone using Tapatalk
    Well, if it's hot and dry when you do it I might suggest misting the exposed plaster every once in a while to keep it cool until the water has been replaced.
    TFP Moderator 39 X 18 23,000(ish) freeform gunite; built 2007ish; Pentair Triton II TR100 600lb Sand filter; 2 HP Pentair pump with 2.2 HP AO Smith single speed motor; 2 skimmers, 1 main drain, 4 returns w/waterfall, Stenner 45MHP2 3GPD running@ 60% - 15 gal Tank; heated by the sun CYA 200+ when I started - 50 now. Dolphin Supreme M5 Pool Cleaner. Hot Springs SX Spa, 285 gallon

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    Re: Do I really need to replace 50% of my water?

    With the amount of rain you have been getting up in the DFW area you could hook up PVC to your gutter system to fill your pool with rain water after you drain it.
    28k gal/raised spa, IG quartzscape, WhistperFlo 2 speed B2984T,DEV60 filter,Lxi400 NG heater, Polaris 280 cleaner, DIY Chlorine injection, Build completion 7/2013

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    Mod Squad pooldv's Avatar
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    Re: Do I really need to replace 50% of my water?

    I would do about 1/3, that will get CYA to a manageable level. Rain and splashout will lower it further.
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    Re: Do I really need to replace 50% of my water?

    I noticed you tested PH when FC was 13 earlier. There is no need to test PH when your FC is above 10 as it will give a false reading.
    Lisa
    Intex AG vinyl 15' x 48" 4,300 gallons due to skimmer install, Krystal Clear SF pump combo 2800 GPH, Krystal Clear SWG, Pool Blaster Max vacuum, Hayward thru the wall skimmer, TF 100 test kit with speed stir, K 1766 Taylor salt test, My SLAM Process

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    Re: Do I really need to replace 50% of my water?

    After draining and refilling about 24" of water and adding 3 gallons bleach 1 hour ago.



    Looking good.

    Next up is overnight test.


    ~21,000 Gallon Kidney Shaped Plaster Pool
    2 feet shallow to 8 ft deep end
    Only one skimmer, and two return jets plus Polaris 280 Jet
    Dallas, TX - West Side of House = HOT
    48 SqFt DE Filter

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    Re: Do I really need to replace 50% of my water?

    To preempt the question, the app is called boximize. It isn't pool specific. It lets you set up your own database using whatever fields you'd like. You can export to excel if you want. Free. I'm unaffiliated, but it gets the job done.


    ~21,000 Gallon Kidney Shaped Plaster Pool
    2 feet shallow to 8 ft deep end
    Only one skimmer, and two return jets plus Polaris 280 Jet
    Dallas, TX - West Side of House = HOT
    48 SqFt DE Filter

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    Mod Squad tim5055's Avatar
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    Re: Do I really need to replace 50% of my water?

    Quote Originally Posted by DallasSocFan View Post
    To preempt the question, the app is called boximize. It isn't pool specific. It lets you set up your own database using whatever fields you'd like. You can export to excel if you want. Free. I'm unaffiliated, but it gets the job done.


    Sent from my iPhone using Tapatalk
    looks neat! Do they have a desktop version or only iOS or Droid?
    TFP Moderator 39 X 18 23,000(ish) freeform gunite; built 2007ish; Pentair Triton II TR100 600lb Sand filter; 2 HP Pentair pump with 2.2 HP AO Smith single speed motor; 2 skimmers, 1 main drain, 4 returns w/waterfall, Stenner 45MHP2 3GPD running@ 60% - 15 gal Tank; heated by the sun CYA 200+ when I started - 50 now. Dolphin Supreme M5 Pool Cleaner. Hot Springs SX Spa, 285 gallon

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