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Thread: Adding acid daily-help!

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    Adding acid daily-help!

    Due to excessive calcium scaling and staining, I drained and acid washed my pool approx 3 weeks ago. I test my water daily with the TF 100 and do additions according to the Pool Calculator. My TA out of the tap was 180 and it took close to two weeks to get it to 80. Due to the hardness of water in PS, my goal is to keep my pH below 7.4 to ensure the staining doesn't repeat. However, my pH rises .3-.4 daily, here are the current numbers

    CH 320
    TA 80
    FC 4
    TC 4
    CYA 32
    pH yesterday after acid addition 7.3, today 7.6

    Any advice would be appreciated, thanks for all of the help!
    10 x 26 IG gunite/plaster
    7300 Gallons
    Hayward Tristar single speed 1 HP
    Hayward CF C4025
    Pool DOB 1/10

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    Mod Squad Bama Rambler's Avatar
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    Re: Adding acid daily-help!

    List all your equipment and how old the plaster is. Especially any water features.
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
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    Re: Adding acid daily-help!

    The plaster is 3 years old, I do not have any water features and have updated my signature for the rest, thanks
    10 x 26 IG gunite/plaster
    7300 Gallons
    Hayward Tristar single speed 1 HP
    Hayward CF C4025
    Pool DOB 1/10

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    Mod Squad Bama Rambler's Avatar
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    Re: Adding acid daily-help!

    How long do you run your pump per day?
    Are the returns aimed to where they're breaking the surface?

    I'm asking these questions to see if there's something going on with the mechanics.

    I'd let the TA come on down to about 70 and see if that helps.
    Dave J. TFP Moderator
    24' x 52" Round AGP. 2hp/hp SPL Power-Flo 2-speed pump. 200sqft Waterway Cartridge Filter. 45MHP2(3GPD) Stenner Peristaltic Pump
    Pool School ----- Pool Math ----- TF-Test Kit

  5. Back To Top    #5

    Re: Adding acid daily-help!

    The returns are underwater and the pump runs approx 4 hours a day. There shouldn't be any excess aeration going on.
    I did consider taking the TA down to 70, but thought I'd explore other options before this one. I guess I don't have a lot of faith in this approach but will do if other options aren't obvious, thanks
    10 x 26 IG gunite/plaster
    7300 Gallons
    Hayward Tristar single speed 1 HP
    Hayward CF C4025
    Pool DOB 1/10

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    Re: Adding acid daily-help!

    Are you saying you don't have faith in lowering the TA? I'm not sure what you mean. I would take the TA down to 60. It's inexpensive and fairly easy to do if you can introduce some aeration.
    Dave S.
    42k vinyl and concrete pool, 1.5hp pump, 140gpm filter
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    Re: Adding acid daily-help!

    Why do you want the pH to be 7.4? If its to avoid scaling, you just need to be sure your CSI is zero or very slightly negative. Based on your other tests, a pH anywhere below 7.6 should do that. Yes, you can lower the TA and it will help with pH rise, but you will always find that pH finds a "natural balance". As long as that yields an acceptable CSI, I don't fight it. Occasional additions of acid are all that's necessary to maintain that "natural balance". Fighting it without lowering the TA is a losing battle.
    chiefwej
    Tucson, AZ
    16x36 rectangular (19k) Pebble Tec play pool/spa, Pentair Intelliflo VS 011018, Super II 2hp (spa), Aqua Rite T-15 SWG, Pro Grid 60 DE, Hayward H400 & Heliocol Solar heating, A&A infloor system, fill water w/high CH and TA, 50 ppm borates,TF-100 test kit

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    Re: Adding acid daily-help!

    Dave, I don't have aeration, but I have slowly lowered in anyway. I thought 80 would be perfect as it is the low end of the scale. However I have been reading that if CH is high enough, then lowering it more is safe?

    chiefwej, is it possible that the pH will find the "natural" balance if I let it go to 7.8? It is currently 7.6, maybe I will skip the addition and see what it does overnight. If it continues to climb, I will lower the TA as advised

    Thanks!
    10 x 26 IG gunite/plaster
    7300 Gallons
    Hayward Tristar single speed 1 HP
    Hayward CF C4025
    Pool DOB 1/10

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    JasonLion's Avatar
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    Re: Adding acid daily-help!

    There really isn't anything to worry about with your numbers where they are now. The PH could go up to 8 and you are still exceedingly unlikely to have any issues with calcium scaling. CSI up to +0.30 is considered just fine and a little higher than that is also fine as long as there isn't any chance of the PH going up further.

    The amount of PH drift you experience is a function both of the TA level and the current PH. Higher TA means more PH drift and lower PH means more PH drift. The lower you try to keep the PH, the more you are going to have a problem with it. You can almost certainly get rid of the PH drift if you let the PH go up to 7.8 and keep TA between 60 and 80.

    When you eventually add some more fill water, it will raise the TA again, and then you will need to keep the PH a bit lower until the TA comes down again. Once you get TA down to 80 again you can go back to allowing PH up to 7.8.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
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  10. Back To Top    #10

    Re: Adding acid daily-help!

    Jason
    The pH did jump to 8, again, up .4 daily. An oddity is that the TA went down to 70, yet I didn't add any acid yesterday. I tested both twice in case of error. Todays numbers

    CH 320
    TA 70
    FC 2.5
    TC 2.5
    CYA 38
    pH 80

    Lots of changes from yesterday. When plugging these numbers into the pool calculator, I go into the danger zone if I try to bring the TA to 60 and pH to 7.1 to allow the TA to come down...CSI=-.75. It looks as if the only safe way to adjust is to leave the TA at 70 and lower the pH to 7.5, giviing me a CSI of -.29. If I don't find out what is going wrong, I'm going to end of in the same mess that I just cleaned up, as the CH jumped 40 overnight (2 days ago) and for some reason, the TA is dropping as is the chlorine 1.5 (non combined) I don't have any pucks in the water, just using bleach and acid. Any ideas?
    Thanks again!
    10 x 26 IG gunite/plaster
    7300 Gallons
    Hayward Tristar single speed 1 HP
    Hayward CF C4025
    Pool DOB 1/10

  11. Back To Top    #11
    JasonLion's Avatar
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    Re: Adding acid daily-help!

    At best the tests are +-10. So TA of 70 and TA of 80 are essentially the same result.

    The safe range for CSI is from -0.6 to +0.6. And numbers near that range aren't going to cause short term problems. If CSI goes below -1 or above 1 you have something to worry about.

    Using your current readings and a water temperature of 80 degrees I get a CSI of 0.38, which is not in any sense in the "danger zone". If your water temperature is lower then the CSI will be lower but still 0 or above, which is also fine.

    Bringing the PH down to 7.1 for a few hours, or even a few days, is not be a problem, though there really isn't any need to do that. You are trying to make very small changes to TA, so there is no need to make huge changes to PH.

    With CH in the 300s and TA below 100 there really isn't anything to worry about. You need to pay a lot more attention when/if CH and/or TA go up significantly higher, but where you are now really isn't risking any kind of problem as long as you keep PH even roughly in the normal range.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  12. Back To Top    #12

    Re: Adding acid daily-help!

    I understand what you are saying. The prompt for this thread is that I can't keep the pH down. Yes, the current numbers are ok, but only if I add acid every day. If I go away for a three day weekend, I'm screwed, lol! After reading the initial responses, I bypassed the acid yesterday, hoping it would find its natural balance. But instead it rose its usual .4 from 7.6 to 8!

    The other plan of action was to lower the TA, but if 80 is 70 and 70 is 60, I guess Im already there ? Living in the desert, I need to get the pH under control now before temp are in the high 100's and water temps in the low 90s for three relentless months-hot! We've recently had temps in the high 90's to low 100's and this evaporation has raised the CH and CYA. So yes, where I am now is ok, but the pH does not stay in the normal range without daily acid additions. As the heat turns up and the CH and TA climb, I expect this battle to continue.

    I hear you saying all is good ? but Im not understanding why. Am I missing something?
    Thanks for your time, I greatly appreciate the feedback!
    10 x 26 IG gunite/plaster
    7300 Gallons
    Hayward Tristar single speed 1 HP
    Hayward CF C4025
    Pool DOB 1/10

  13. Back To Top    #13

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    Re: Adding acid daily-help!

    Overall, evaporation does not affect your CYA. It might go up a little when your pool level is low, but should fall right back into place when you add water back.
    Built in 1957 44,000 gallon in-ground, Wet Edge Primera Stone in Sky Blue, Intelliflo VF Pump, 600 lb. Pentair Triton II TR-100 Sand Filter, CircuPool RG 60 Plus SWG, TF-100 test kit
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  14. Back To Top    #14
    JasonLion's Avatar
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    Re: Adding acid daily-help!

    Your TA is currently 70-80. You can lower it to 60 safely. Lowering TA will lower the rate of PH increase. You can still lower TA a little more (down to 60 on the test) without problems. If you really need to you can add borates, and then you can lower TA even further (down to 40).

    The PH does not increase without bound. It will stabilize at around 8.4. You still want to maintain PH below 8, but if something goes wrong the PH won't go above 8.4. You are safe right now because even with PH at 8.4 your CSI is still only marginal, not horrible. As long as it doesn't sit at 8.4 for too long there won't be issues.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

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    Re: Adding acid daily-help!

    I have been managing my pool with very high CH levels for a couple years now, with no scaling. I just reduced the TA and then added borates. That makes it much easier to maintain a reasonable CSI even with CH levels near 1,000. I'm planning on draining and refilling this spring, but my fill water starts out about 375 CH. With desert heat and evaporation rates here in Tucson, CH will be back sky-high again in no time.
    chiefwej
    Tucson, AZ
    16x36 rectangular (19k) Pebble Tec play pool/spa, Pentair Intelliflo VS 011018, Super II 2hp (spa), Aqua Rite T-15 SWG, Pro Grid 60 DE, Hayward H400 & Heliocol Solar heating, A&A infloor system, fill water w/high CH and TA, 50 ppm borates,TF-100 test kit

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    Re: Adding acid daily-help!

    OK, so I have had my TA stabilized at 50-60 for over a week, but the pH is still increasing .3 every day.
    Here are the numbers for the last 4 days. With the exception of pH, assume other readings remain the same....I have added chlorine to maintain 3ppm, but have held off on acid additions to see what it would do. Is there anyway that this daily increase in pH is "normal" in warm, sunny climates? I don't know what else to do.

    CH 400
    TA 60 60 60 60
    pH 7.1 7.5 7.8 8.1
    TC 3
    CC 0
    FC 3
    CYA 30


    As always, I appreciate the help!
    10 x 26 IG gunite/plaster
    7300 Gallons
    Hayward Tristar single speed 1 HP
    Hayward CF C4025
    Pool DOB 1/10

  17. Back To Top    #17
    Richard320's Avatar
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    Re: Adding acid daily-help!

    Quote Originally Posted by palmspriings
    OK, so I have had my TA stabilized at 50-60 for over a week, but the pH is still increasing .3 every day.
    Here are the numbers for the last 4 days. With the exception of pH, assume other readings remain the same....I have added chlorine to maintain 3ppm, but have held off on acid additions to see what it would do. Is there anyway that this daily increase in pH is "normal" in warm, sunny climates? I don't know what else to do.

    CH 400
    TA 60 60 60 60
    pH 7.1 7.5 7.8 8.1
    TC 3
    CC 0
    FC 3
    CYA 30


    As always, I appreciate the help!
    I add acid 2-3 times a week with my TA bouncing between 50 & 60. CH is over 800. I believe the TA increase and the pH rise is because I am slowly stripping scale off the walls. Maybe that's what's happening with you, too.
    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!

  18. Back To Top    #18

    Re: Adding acid daily-help!

    Richard
    Thanks for the response. I just had all of the scaling removed, so I was hoping for more stablization with this pH. Afraid to leave town, you know
    10 x 26 IG gunite/plaster
    7300 Gallons
    Hayward Tristar single speed 1 HP
    Hayward CF C4025
    Pool DOB 1/10

  19. Back To Top    #19
    Richard320's Avatar
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    Re: Adding acid daily-help!

    Quote Originally Posted by palmspriings
    Richard
    Thanks for the response. I just had all of the scaling removed, so I was hoping for more stablization with this pH. Afraid to leave town, you know
    You have room for more CYA. And trichlor is acidic. I suggest you get a floater and a small bucket of pucks. It will raise CYA, maintain FC, and maintain pH for you while you're gone.
    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!

  20. Back To Top    #20

    Re: Adding acid daily-help!

    Quote Originally Posted by Richard320
    Quote Originally Posted by palmspriings
    Richard
    Thanks for the response. I just had all of the scaling removed, so I was hoping for more stablization with this pH. Afraid to leave town, you know
    You have room for more CYA. And trichlor is acidic. I suggest you get a floater and a small bucket of pucks. It will raise CYA, maintain FC, and maintain pH for you while you're gone.
    Already have these ready to go.....it's my summer plan Richard! I'm keeping my CYA on the low side for now, so I can use the pucks in the summer. Chasing both pH and chlorine is not on my agenda :P
    10 x 26 IG gunite/plaster
    7300 Gallons
    Hayward Tristar single speed 1 HP
    Hayward CF C4025
    Pool DOB 1/10

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