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Thread: Hardness in Vinyl Pool

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    Hardness in Vinyl Pool

    So i just got back from Leslies and they told me to put in some hardness plus into our pool. My question is: Is hardness plus really needed in a vinyl pool? I was of the understanding that it really isn't that vital, but i don't know. here are the numbers their test gave me:

    FC: 0
    TC: 0
    pH: 7.8
    TA: 50
    CYA: 40
    Calcium Hardness: 150

    I've already put in some chlorine and plan on baking soda for the Alkalinity tonight after i clean the filter. Do i need to put in the hardness plus?

    thanks!

    -ian
    5400 gal, Vinyl AGP, Hayward 1hp Power-Flo LX pump, 40sqft cartridge Filter (24,000gal/8hr) pool built @2000

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    UnderWaterVanya's Avatar
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    Re: Hardness in Vinyl Pool

    Quote Originally Posted by dustmites
    So i just got back from Leslies and they told me to put in some hardness plus into our pool. My question is: Is hardness plus really needed in a vinyl pool? I was of the understanding that it really isn't that vital, but i don't know. here are the numbers their test gave me:

    FC: 0
    TC: 0
    pH: 7.8
    TA: 50
    CYA: 40
    Calcium Hardness: 150

    I've already put in some chlorine and plan on baking soda for the Alkalinity tonight after i clean the filter. Do i need to put in the hardness plus?
    CH is fine. 50-300 is OK for Vinyl in general.

    Free Chlorine is awful. Needs to be addressed immediately.

    pH is a little high - could stand to be brought down a bit.

    TA is a little low - could stand to be brought up a bit as you plan. What's the target you want to reach? 80?


    Can you test on your own? The store tests are notorious for not matching home testing and for giving different results with repeat tests of the same sample.
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    JasonLion's Avatar
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    Re: Hardness in Vinyl Pool

    No, there is no reason to add the hardness plus (unless your warranty requires it).

    Maintaining your FC level is very important, as UnderWaterVanya points out.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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    Re: Hardness in Vinyl Pool

    Thanks for the reply!

    I have a DPD Deluxe kit from Leslies, so I can't really test everything. My budget for the pool this year took a rapid decline when i had to buy a new pump, so the testing kit got the short end of the stick. I'll start testing on my own tonight with the kit I have and see if I can get consistent results. I didn't know that the store tests were that varied. You'd think it would be more accurate. Oh well.

    Thanks!

    -ian
    5400 gal, Vinyl AGP, Hayward 1hp Power-Flo LX pump, 40sqft cartridge Filter (24,000gal/8hr) pool built @2000

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    dmanb2b's Avatar
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    Re: Hardness in Vinyl Pool

    Welcome to TFP!

    If those are truly your test results (again, they can be varied quite a bit), you have received very solid advice above. Testing on your own water and getting a "feel" for your chemistry via consistent test results and understanding how certain chemicals impact that chemistry is truly the key to "BBB".

    You may have mentioned this already, but what are you using to chlorinate?
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    Re: Hardness in Vinyl Pool

    Right now I'm using 6% Clorox bleach. It takes a few cups to get the FC higher, but I can get 4.5 gallons for 10$, so it works out.

    I've also found some dry acid I forgot I had and will use to lower the pH a little.

    As for a warranty, I don't think the warranty is transferable between owners, or at least, the previous home owner did not mention a warranty, though I can look around for documents.
    5400 gal, Vinyl AGP, Hayward 1hp Power-Flo LX pump, 40sqft cartridge Filter (24,000gal/8hr) pool built @2000

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    dmanb2b's Avatar
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    Re: Hardness in Vinyl Pool

    I would not add any more dry acid until you can reverify PH on your own, but if you must, please add some baking soda to raise TA by around 10. Adding acid will also lower TA, and TA below 50 can cause unstable PH.
    24'x52" AGP (13,500 Gallons), Intex SWG, (2)Solar Bear 4x20 panels, Hayward S220T Filter, 1/2hp Pentair Superflo

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    UnderWaterVanya's Avatar
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    Re: Hardness in Vinyl Pool

    Quote Originally Posted by dustmites
    I have a DPD Deluxe kit from Leslies, so I can't really test everything.
    What does that test kit cover?
    Inlaws Pool Boy since June 14th 2012, Pool built ~ 2003, In-Ground, 16'x32'
    13500 gal, Vinyl Liner, Fiberglass Slide, TF-100 Test Kit, Hayward 210T
    sand filter, A.O. Smith 1.5HP main pump motor (C48L2N134C1),
    Hayward SuperPump (model ?), Polaris 380 & PB4 Booster Pump

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    dmanb2b's Avatar
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    Re: Hardness in Vinyl Pool

    Quote Originally Posted by UnderWaterVanya
    Quote Originally Posted by dustmites
    I have a DPD Deluxe kit from Leslies, so I can't really test everything.
    What does that test kit cover?
    A DPD deluxe is esentially a rebranded Taylor K2005. It can test everything that a K2006 can test for or a TF100 can, except it does not have the FAS-DPD test and is limited in testing of FC/CC...but outside of that, it is better than most, so I would trust those tests before I would Leslie's. Just my opinion.
    24'x52" AGP (13,500 Gallons), Intex SWG, (2)Solar Bear 4x20 panels, Hayward S220T Filter, 1/2hp Pentair Superflo

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    Re: Hardness in Vinyl Pool

    That is actually *really* useful to know. I had gotten it thinking I'd be able to use it for the overnight superchlorination, but sadly, it does not test for chlorine levels above 5. So I had held off using it at all, thinking that I really really should get the FAS-DPD test, and that Leslies tests should give FAS-DPD levels of accuracy. Turns out they don't, and I really didn't want to bring in a sample every hour to Leslies :P

    thanks a ton for the help!

    -ian
    5400 gal, Vinyl AGP, Hayward 1hp Power-Flo LX pump, 40sqft cartridge Filter (24,000gal/8hr) pool built @2000

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    Re: Hardness in Vinyl Pool

    You can order just the FAS-DPD test from here, http://tftestkits.net/cart.html?m=splash, then you will have the tests you will need. You can also order any other single test items that you might want.
    16k gal plaster with raised spa, Jandy DEV60 filter, 2 HP 2-speed SHPF Jandy Stealth pump
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    Re: Hardness in Vinyl Pool

    So I tested earlier and got the following:

    FC 0
    TC 0
    PH 7.8
    TA 120

    My concern now is that my chlorine seems to disappear astonishingly quickly. I put in enough on Monday to kick it up to 4ppm but its gone now, or at least that's w

    hat the test tells me. Is it normal for it to disappear so quickly?

    Thanks
    Ian
    5400 gal, Vinyl AGP, Hayward 1hp Power-Flo LX pump, 40sqft cartridge Filter (24,000gal/8hr) pool built @2000

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    dmanb2b's Avatar
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    Re: Hardness in Vinyl Pool

    What is your CYA level? It could have. You'll want to first lower your PH to 7.2 and then get FC up asap, perform the overnight chlorine loss test and shock if needed.
    24'x52" AGP (13,500 Gallons), Intex SWG, (2)Solar Bear 4x20 panels, Hayward S220T Filter, 1/2hp Pentair Superflo

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    Re: Hardness in Vinyl Pool

    You can figure a 2-3 point loss a day to be about average for pools if all is well. When you have organics in the water this amount will rise. With your CYA at 40 you should maintain 3 ppm of chlorine at minimum and should try to have 5 ppm at all times. When you start dropping below 3 ppm, that's when the algae can get a foot hold in the water and you will continuously be losing too much chlorine.
    16k gal plaster with raised spa, Jandy DEV60 filter, 2 HP 2-speed SHPF Jandy Stealth pump
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    Re: Hardness in Vinyl Pool

    sure would like an answer to his question performed calcium hardness test on my vinyl pool got a 70 reading went to pool store they sold me hardness plus and I have not used. because everything I'm reading seems to say you don't have to worry about it in a vinyl pool. Is this correct if so I will return the stuff

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    Mod Squad JVTrain's Avatar
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    Re: Hardness in Vinyl Pool

    Hardness for a vinyl pool is mostly irrelevant. As long as it's above 50 and not well above 300, no sense in adjusting at all. Even if hardness was 500, likely no issues other than maybe some evaporation scale at the water line.

    You need to get a FAS-DPD test to check your CC level and get accurate FC above 5 ppm. By how fast your chlorine is consumed, you likely have an algae problem. You also need an accurate, at-home CYA test. You can get that with a K-2006 Taylor kit or the TF-100/TF-50 from tftestkits.net. You'll get great service and pricing from them.
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