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Thread: Starting numbers, issues

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    Starting numbers, issues

    Hi, I'm Oscar, new to the board.

    Just bought a house with an IG pool, and luckily it was in decent shape to begin with. Got my TF100 today, ran a couple tests more than once to confirm accuracy, here are my values today...

    12,000 gal
    80 deg F
    pH 7.5
    FC 13
    CC 0
    TC 13
    CH 500
    TA 90
    CYA 100

    I know CYA is high, debating dropping some water and refilling vs waiting for rainy season to kick in in a couple months here.
    CH a little high too, same debate.

    Previous owner had a pool company come weekly who used stabilized tablets in a floater, thus the high CYA. I left it until today when I could run good numbers myself, will now manually chlorinate, most likely with pool store liquid chlorine.

    I understand the FC number is about right per the CYA chart, but does this not make the water seem overchlorinated to the swimmer? I've seen it said that over 5 ppm is high enough to close a pool. Pool math also tells me that shocking will take about 2.5 gallons, this is to be done weekly?

    Got some other issues, but will get to that later, chemistry first, pic here... http://tinyurl.com/mmf27hy
    12,000 gal IG, Diamond Brite, built 1957. 90 sq ft Hayward Star Clear Plus, 1 HP Sta-Rite pump, TF100

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    Smykowski's Avatar
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    Re: Starting numbers, issues

    Welcome to the forum!

    If you replace water to drop the CYA, the CH will come down too.

    As to your FC question, no, the swimmers won't notice because CYA buffers the chlorine. I usually keep my FC in the 8-10 range because of my CYA level, and nothing makes me happier than when guests say, "Wow, how do you keep your pool so clean without chlorine?"
    33' round, 23,000 gal AG vinyl , 1HP 2spd PowerFlo Matrix downsized with 3/4HP impeller (X2), Hayward S180T 150# sand filter (X2), Hayward H250 NG heater Pool Store year 1 - $850 for 2 months; Pool Store year 2 - $440 for 2 months, TFPC year 1 - $170 for 4 months; TFPC year 2 - $95 for 4.5 months
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    Mod Squad kimkats's Avatar
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    Re: Starting numbers, issues

    Quote Originally Posted by Oscar7 View Post
    Pool math also tells me that shocking will take about 2.5 gallons, this is to be done weekly?

    Shocking is not needed with your levels and how your water looks. We really do not use the term shock. It is called SLAM. There is a link on how to do a SLAM but you should never need to do it if you follow the TFP way!

    You will add chlorine daily to "feed" the pool. I add mine at just after dark and let the pump run for 30 mins. or so to mix it in (I run the pump during the day and turn it off when I get home). I do this to let the chlorine do it's job without worrying about the sun using it up.

    I would go ahead and drain/refill your water to work on your CYA. Lower CYA will be cheaper and easier to maintain due to not needing as much chlorine. Here is the chart to show you the needed levels of chlorine for the different CYA levels.

    http://www.troublefreepool.com/conte...art-slam-shock

    Your CYA may be even higher. You might want to do the 50/50 test. Here is a link to how to do it. Opps I cannot find the link. I hope someone will come along to show it to you.

    Good luck and let us know what your other questions/issues are.
    TFP Moderator 33x52 round AG 25,600 gals Sand Filter 1.5hp Pump - 2 Speed, SLAM, Pool School, Recommended Levels, Recommended Chemicals, Pool Math, Chlorine/CYA Chart, TF-100 Test Kit

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    Re: Starting numbers, issues

    48 hours after my first post, I ran some tests and am writing this. Haven't added bleach since I pulled the trichlor floater 2 days ago. In 48 hours, FC dropped from 13 to 8.5. As per my previous CYA result of 100, I added about a half gallon 10.5% pool store chlorine to bring it up to a goal of 12. I tested FC again about an hour after adding, came up with 15. A little high, but I also probably poured too much bleach and will have to start actually measuring.

    When I first tested CYA myself I got 100 right on the mark, which made sense because three tests done by local Pinch a Penny in the last 3 weeks all came up 95.

    I just ran a CYA test and a 50/50 test back to back, and both came up 60. I removed the trichlor floater 2 days ago and replaced maybe 300-400 gallons, not a lot. Is there a reason for this discrepancy? I know its a somewhat subjective test and my eyes are pretty lousy for a 30 year old, but I ran it a number of times to the same result. Either way, my FC is high for the suggested 8 at a CYA of 60, though I'm adding about 300 gallons now and it should drop off soon enough.
    12,000 gal IG, Diamond Brite, built 1957. 90 sq ft Hayward Star Clear Plus, 1 HP Sta-Rite pump, TF100

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    Mod Squad woodyp's Avatar
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    Re: Starting numbers, issues

    How sure are you about your # of gallons in your pool?
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    Re: Starting numbers, issues

    I could definitely be off by a bit, calculated by taking measurements of the size and the depth front and back, assuming a constant slope, and the pool is off square, so had to do two rectangle calculations and about half the second. Pretty significant margin of error. Click here to see the shape: http://tinyurl.com/mmf27hy
    12,000 gal IG, Diamond Brite, built 1957. 90 sq ft Hayward Star Clear Plus, 1 HP Sta-Rite pump, TF100

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    Mod Squad woodyp's Avatar
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    Re: Starting numbers, issues

    Rely on your liquid bleach chlorine additions to TELL you whether your gallons are higher or lower than you THINK they are. Pool Math doesn't lie! If adding X amount of bleach should raise your FC by X amount for the gallons you declare and then it tests higher, your gallons size is obviously overstated.
    16x32x52" Steel Cornelius Miramar AGP Vinyl liner 13,100 gal. Buried 2 ft.
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    Mod Squad tim5055's Avatar
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    Re: Starting numbers, issues

    Of all the tests the CYA is the most subjective. Lighting, where you hold the tube or several other issues will impCt the results. I ignore swings of about 5 - 10 myself, but I'm getting old with the eyes that go along with that. When you do the test you can pour the solution back and forth between the mixing container and the reading tube several times to get an average number.

    I would ignore Pinch a Penny and their results as they are even worse at the test than we all can be. They are doing the test indoors under artificial lighting and I think that has something to do with it.

    As woodyp said, if you pay attention to what pool math says should happen when you add chemicals and what really does happen you will get a feel for your pool volume and weather what you think it is is correct.
    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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    Mod Squad woodyp's Avatar
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    Re: Starting numbers, issues

    "They are doing the test indoors under artificial lighting and I think that has something to do with it."-----------tim5055

    Most definitely does!
    16x32x52" Steel Cornelius Miramar AGP Vinyl liner 13,100 gal. Buried 2 ft.
    2 Speed Hayward Power-Flo Matrix 85 g.p.m. 22" 250lb. sand filter hard plumbed
    Pool Rover Jr., Pool Blaster Max, Diver Dave TF100 Test Kit/Speed Stir
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    Mod Squad tim5055's Avatar
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    Re: Starting numbers, issues

    Quote Originally Posted by woodyp View Post
    "They are doing the test indoors under artificial lighting and I think that has something to do with it."-----------tim5055

    Most definitely does!
    Hey, I've had a couple of adult beverages tonight - I was trying to be nice
    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: Starting numbers, issues

    Maybe a dumb question, but when you did the dilution test, did you multiply your result by 2? Is CYA 60 or 120?

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    Re: Starting numbers, issues

    Quote Originally Posted by MarianParoo View Post
    Maybe a dumb question, but when you did the dilution test, did you multiply your result by 2? Is CYA 60 or 120?
    I did multiply, CYA is 60. I did the test standing outside under shaded afternoon sunlight. I dripped test water into the view tube until the black dot was absolutely occluded and all I saw was uniform white. Ran 50/50 twice, both put the water right at 30 mark, then straight test brought water right to 60 mark. It would seem to me that the 50/50 is more accurate as the lines are far closer higher on the scale.
    12,000 gal IG, Diamond Brite, built 1957. 90 sq ft Hayward Star Clear Plus, 1 HP Sta-Rite pump, TF100

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    Mod Squad tim5055's Avatar
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    Re: Starting numbers, issues

    Quote Originally Posted by Oscar7 View Post
    I did multiply, CYA is 60. I did the test standing outside under shaded afternoon sunlight. I dripped test water into the view tube until the black dot was absolutely occluded and all I saw was uniform white. Ran 50/50 twice, both put the water right at 30 mark, then straight test brought water right to 60 mark. It would seem to me that the 50/50 is more accurate as the lines are far closer higher on the scale.
    doing it both ways reinforces it. Actually the dilution test is usually a little less accurate.

    If you did the test in full sun you may even be at 50.....
    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: Starting numbers, issues

    Now that you have done a partial refill and your CYA is lower, did you recheck your CH?

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    Re: Starting numbers, issues

    Ran a full set of numbers again:

    80 F
    pH 7.8
    FC 12
    CC 0
    CH 450 brought first noticable color change, two more drops to 500 brought full change, which are we going for?
    TA 80 again brought change when the drop went in but none when swirled, 90 to full change
    CYA 65, pretty confident on this number, ran twice with same sample

    I dropped my estimation to 10,000 gallons, figuring on adding 5.4 oz muriatic to bring pH to 7.6 and not let it get so high. Test FC again tomorrow but probably not have to add bleach till the day after.

    I only changed a few hundred gallons so didn't expect CH to drop much at all.
    12,000 gal IG, Diamond Brite, built 1957. 90 sq ft Hayward Star Clear Plus, 1 HP Sta-Rite pump, TF100

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    Smykowski's Avatar
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    Re: Starting numbers, issues

    You're looking for full color change. If the drop makes the color change, count it and keep going. If the drop doesn't make the color change any further, stop, you're done, and ignore that last drop.
    33' round, 23,000 gal AG vinyl , 1HP 2spd PowerFlo Matrix downsized with 3/4HP impeller (X2), Hayward S180T 150# sand filter (X2), Hayward H250 NG heater Pool Store year 1 - $850 for 2 months; Pool Store year 2 - $440 for 2 months, TFPC year 1 - $170 for 4 months; TFPC year 2 - $95 for 4.5 months
    The most important article on this site - The ABCs of Pool Water Chemistry

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    Re: Starting numbers, issues

    Quote Originally Posted by Smykowski View Post
    You're looking for full color change. If the drop makes the color change, count it and keep going. If the drop doesn't make the color change any further, stop, you're done, and ignore that last drop.
    Cool, then CH steady at 500 and TA at 90.

    I'm assuming pH should be kept in the middle as much as possible, around 7.6?
    12,000 gal IG, Diamond Brite, built 1957. 90 sq ft Hayward Star Clear Plus, 1 HP Sta-Rite pump, TF100

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