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Thread: ph

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    ph

    does ph rising correlate with rise in alkalinity. My local pool store tests my water and tells me to add acid and raise alkalinity with balance pack because ph is 7.5 while total alkalinity is 83.
    I also want to know why it shoulld take 50 gallons of liquid chlorine at pool start up this spring to reach a level of free chlorine inspite of pool opened by pool installer built in 2011 as 20x40 gunite and needed that much in 2012 and 2013

    Joe D
    16 x 32 Grecian Vinyl. Salt-Aqua Plus PS-4, Hayward Pro Series Sand Filter, Hayward Ecostar SP34000vsp, Gulfstream HE-125-T-A Heat/Cool heat Pump

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    Charlie_R's Avatar
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    Re: ph

    If you go to the upper right of this page, there is a large button, labeled Pool School. Click on it, and enjoy several hours of reading and learning.

    Next you should consider taking control of your pool, which will mean buying a good test kit (http://tftestkits.net/) and learning how to use it.

    The pH and TA (Total Alkalinity) you report, many people here struggle to attain.

    Next you should add your pool info to your signature line, so we know what size and volume your pool is, and if you have an SWG, along with any other equipment (filter, pump, etc). You can do this from the User Control Panel.

    There is NO residential pool I've ever heard of that would need 50 gallons of liquid chlorine to start, especially one guestimated (http://www.poolcalculator.com) at only 29900 gallons, assuming an average depth of 5 ft. That would raise your FC by 209, which could damage the pool and equipment.
    15'x48" 4500 gallon Intex pool, buried 1.5 ft. Pac-Fab Dynamo 3/4 hp pump. Hayward S180T sand filter, bought used. Taylor K-2006 test kit. Rocket mass heater based wood fired pool heater.

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    Patrick_B's Avatar
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    Re: ph

    Welcome to the Forum Joe. Glad you came here to learn about your pool chemistry.

    Rising pH correlates with an already high(er) alkalinity. Higher pH waters have more alkalinity and that causes the pH to rise more quickly. More acidic, or lower alkalinity waters have less tendency to rise but are less stable and tend to swing more in either direction with regard to pH. Alkalinity represents the amount of buffering capacity a given sample of water contains. More alkalinity equals more buffering capacity.

    You can actually raise the pH without raising the alkalinity through aeration such as a waterfall or similar, or a Salt water Chlorine generator. You can also raise alkalinity without raising the pH a great deal by adding baking soda (sodium bicarbonate). The latter is not necessarily something you want to do, and often is not. Your alkalinity is just about perfect at 83 and so is your pH at 7.5. Adding acid lowers pH and alkalinity, and that is a simple fact. Alkalinity and pH are intertwined in a very complex way, and how one effects the other is dependant upon many factors.

    As for the amount of Chlorine it took to open, there are some questions that need to be answered. First, how deep is your pool? A 20X40 pool will have a lot of capacity with a very deep end. What shape was the pool in? Was it green or black water upon opening? What else was put in the pool in the past?

    Here, we have the philosophy of maintaining our pool chemistry by testing it ourselves with very accurate and dependable testing methods, and understanding what adding any product does. As a rule, we don't trust or follow pool store suggestions because the advice is often wrong, and their test results inaccurate. We encourage others to learn and understand exactly what is going on with their pool and be in complete control through knowledge and understanding. Everything we teach you can learn and most of it is in Pool School. Anything you don't find or understand will be answered by one of the many helpful folks here on the boards. Lastly, and most importantly, this control can't be gained without the use of a quality test kit. Without one, you are flying blind so we strongly encourage you to get one and post results so we can help you properly.

    Hang around, read, and enjoy the forum.
    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

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    Smykowski's Avatar
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    Re: ph

    Welcome to the forum. Charlie and brushpup gave you good answers.

    This is why we don't use pool store recommendations. In your case, those instructions are a borderline ripoff. I'd need to see a full set of accurate test results to give a complete recommendation, but at first glance a pH of 7.5 and a TA of ~80 should need no adjustment right now.
    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: ph

    I work for a pool company and as part of the services we offer, we do free water testing. We use a software package that analyzes the results, and recommends what chemicals are needed to balance the chemistry. The software is provided by our chemical distributor. Needless to say, it is designed to sell more chemicals. We typically recommend about half of whatever the software tells us.

    Don't trust the pool store. Learn what you can from this forum, and use that information to guide you. You will save a fortune in the long run, and your pool will be clear and balanced with none of the frustration.
    TreeFiter

    Pool Technician
    Saugerties, NY

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    Re: ph

    One reason that 50 gallons of liquid chlorine could be needed would be if some of your cyanuric acid were converted to ammonia by bacteria. It's not common, but it does happen. What were your CYA at close and open.

    If that did happen, they should have told you.

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    Charlie_R's Avatar
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    Re: ph

    JamesW,

    Even if that were the case, there would be NO reason for them to recommend that high a dose all at once. I can see 5 doses at 10 gallons each, spread over 10 hours, but one massive dose?
    15'x48" 4500 gallon Intex pool, buried 1.5 ft. Pac-Fab Dynamo 3/4 hp pump. Hayward S180T sand filter, bought used. Taylor K-2006 test kit. Rocket mass heater based wood fired pool heater.

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    Patrick_B's Avatar
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    Re: ph

    I don't think he stated one massive dose, just that it took 50 gallons. I assumed it was over some period of time. Let's see what the OP meant when a new response is given.
    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

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    Re: ph

    I was thinking that it was cumulative, not all at once.

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