Become a TFP Supporter Pool Math Forum Rules Pool School
Results 1 to 4 of 4

Thread: hard water, low pH

  1. Back To Top    #1

    Join Date
    Jan 2015
    Location
    Fort Thomas, KY
    Posts
    8

    hard water, low pH

    I opened my pool for hte first time on my own this year and then let it sit for a couple weeks (I know that was a big mistake) it was cloudy and so I threw in about 6 gallons of liquid chlorine and then 12 gallons. the chlorine levels were still low (was using test strips) pH was also low. I threw in about 8 pounds of baking soda and the pH didn't budge. I bought a test kit and it takes about 20 drops of reagent to get the pH up to the right level. I checked the hardness and it takes about 30 drops to get the correct color change. I spoke with a woman at Leslie's and she said I must have metal in the pool to have things that far out of whack. I got metal free and ran that for 3 days. the water is less cloudy but that may be more related to acid washing the cartridges (both before and after the metal free.) I am unclear as to how the pH can be so low with such hard water. seems like normally that causes higher pH. I would try to SLAM the pool, but the pH has to be in the proper range to do this. Do I just need to be more agressive with alkali? I put another 7 lbs of baking soda in tonight with no significant results. I understand that is a weak alkali. should i be using Borax or at least soda ash? do I need to fix the hardness (drain and refill) before I can fix the pH?

    Thanks for any thoughts or direction.
    20x40, inground, 37,500g, gunite, heated, cartridge filter, polaris cleaner, haywood chlorinator

  2. Back To Top    #2
    Texas Splash's Avatar
    Join Date
    Jun 2014
    Location
    South-Central Texas, Marion/San Antonio
    Posts
    12,979

    Re: hard water, low pH

    Good morning! It sounds like perhaps your biggest obstacle in all of this is that you aren't testing the water on your own with a TF-100 (XL Option) or Taylor K-2006C. Much of your frustration and perhaps lost $$$ could've been saved by now. It would be in your best interest to order one of those kits (TF-100 link below). They are not difficult to use, and I know you will not regret it. When you order though, make sure to also order the "Speed Stir" for easy mixing. With either of those kits, post a full set of test results and you'll be amazed the changes you can make for your water. Anything else, even with pool store tests, is a gamble on guessing.
    Pat (a.k.a. Texas Splash) ~ My Pool: Viking Fiberglass; 17,888 Gal; Waterway Supreme 2-sp/2-hp pump; Hayward Ctg filter; TF-100 w/ Speed Stir
    Vital Links: POOL SCHOOL, RECOMMENDED LEVELS, RECOMMENDED CHEMICALS, Poolmath Calculator, SLAM, Chlorine/CYA CHART.
    If you enjoyed your TFP experience, please consider donating to Support TFP!

  3. Back To Top    #3
    Richard320's Avatar
    Join Date
    Jan 2010
    Location
    San Dimas, CA (LA County)
    Posts
    18,768

    Re: hard water, low pH

    Don't confuse hardness with pH.

    Hardness is the measure of Calcium dissolved in water. If you live in an area with a lot of limestone, you're just plain stuck with it. It could also come from overuse of Cal-hypo chlorine powder. pH is a measure of whether the water is acidic or basic. Chemically, they're unrelated. You could mix a bunch of lye into some distilled water and have really high pH and no hardness. In real life, generally, "hard water" means high Calcium and high alkalinity. High alkalinity drives the pH up. But that's water straight out of the tap. What happens to pool water when some yahoo pool tech starts selling you buckets of potions and powders is a whole 'nother story.

    As an aside, baking soda raises total alkalinity (TA) but has very little immediate effect on pH. Had you used Washing Soda aka Soda Ash, things would have jumped dramatically. As it is now, the higher TA will start to push the pH upwards, but it could take days or weeks.

    What test kit did you buy? There's really only two we recommend. If you got the three way kit, you're missing a couple tests. If they sold you a Taylor K-2005, you're almost there. You can buy just the components that are missing.

    Post up some results in the format we're used to and tell us what kind of test kit you have and what kind of equipment and we'll try to get you on the right track. Don't forget to tell us how the water looks, because that affects our advice. Clear/murky/cloudy/green/black?
    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!

  4. Back To Top    #4

    Join Date
    Jan 2015
    Location
    Fort Thomas, KY
    Posts
    8

    Re: hard water, low pH

    Thank you both for your input. I do have a Taylor kit so I'll have to look into padding that up a bit. The water is actually much more clear as I got home today and it seems to be improving in the pH at least a little bit. Still below 6.8 though. It's also holding some chlorine from the chlorinator which seems encouraging. I'll probably super chlorinate tonight and I did get some soda ash so I'll see if that'll bring the pH up the rest of the way. If I continue to have problems I'll get some real numbers and post them back. Thanks again


    20x40, inground, 37,500g, gunite, heated, cartridge filter, polaris cleaner, haywood chlorinator

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •