Jump to content

pH and Borates


jaredthomas27

Recommended Posts

Good afternoon all.  Have a question I am hoping to get clarification on please.  I have 50 ppm of borates in my water via boric acid.  Will that slow or stop my ability to lower my pH with muriatic acid?  My TA got down to 48 (testing with K2106 drop test) accounting for the borate correction factor in the book and my pH is still hovering around 7.9-8.0  I have bumped my TA up to 88 with baking soda to give myself room to add more acid but I just added .5oz of acid and my pH remained unmoved.  Could that be because of the borates?  I am measuring pH with a calibrated Apera electric meter my wife uses for work for exact precision.  I am running the 3 step Bromine.  Thanks in advance!

Link to comment
Share on other sites

I have exactly the same issue!  Have borates 50 ppm (added granular boric acid), corrected TA also 48 ppm (Taylor testing) and pH high ~7.9 (tested with Taylor and two different stores)  Water a month old now but noted this issue within 2 wks of deep cleaning, water change and adjusting all chemistries. Using chlorine (just dichlor).

I think somewhere in this forum (by someone knowledgeable) there was a posting indicating with borates not to be concerned and not to adjust unless above 8.0, but also a bit worried.

Any insight helpful! Thanks.

  • Like 1
Link to comment
Share on other sites

From my understanding the borates will help "lock" the PH and make it more stable.  I have personally seen much more stable PH results after I started using borates.  I've never worried about corrected TA because I follow @waterbear's 3-step Bromine instructions, in which you adjust TA first, then worry about PH, then CH, then sodium bromide, then shock with liquid chlorine, and finally add borates.  With the TA already set at the beginning you don't need to worry much about the correction factor.  I've mostly seen the correction factor used with pools, but I could be wrong on that. 

I start on initial fill by adjusting to 70 ppm TA and this tends to lock me in around 7.8 PH after the rest of the water balancing.  My water starts around 7.2 PH from the tap, so it normally takes a day to drift up and "lock" at 7.8.  I don't use any PH up or whatever, it just drifts up.  I've previously fiddled around with acid to bring the PH down to 7.4-7.6 because I was worried about being close to 8.0, but it always just drifted right back to around 7.8 the next day.  After I stopped messing around with trying to have perfect PH and wasting dry acid, I realized my tub's PH basically goes in lock step with the TA.  Eventually over about 6-8 weeks my PH will drift down to around 7.2-7.4, at which point I test my TA and it will have been depleted to around 30 ppm.  At that point I'll top off the water, replenish TA with some baking soda to get back to 70ppm TA, and my PH will drift right back up and lock at the same 7.8.  After the initial fill, not counting the floater, only things I ever add are liquid chlorine to shock, and the occasional water refill and baking soda.  Only caveat is my tub is inside the house, so we minimize splash out, and I don't have to deal with any rain or other outdoor intrusions into the water.  

My advice would be if you are stable at about 7.9 just relax and enjoy the tub.  Higher PH seems to be a usual side effect of 3 step bromine and is fine as long as you stay below 8.0.

  • Like 1
Link to comment
Share on other sites

Water is brand new, filled this weekend after a deep clean.  I did the 3 step method from waterbear but am afraid i may have stopped the pH/TA portion a step to soon (pH at 7.9) and then added the borates.  Retested just a minute ago and pH was up around 8.2 with corrected TA at 53.  Using the acid demand and Taylor table I am adding 1oz (half the recommended 1.9 oz) of muriatic acid and will retest in about an hour.  LIkely going to have to add baking soda to increase TA as im afraid it will drop significantly after this acid addition.

Link to comment
Share on other sites

Again, I'm not the expert, but I believe corrected TA is only applicable when using the (Langelier) saturation index, which is not really applicable to acrylic hot tubs, and is used typically for pools (tiles, grout, gunite, etc.).

What is the uncorrected TA that you measured from the Taylor kit?  I'm thinking you are up at 80 or 90 ppm, which might be too high of a TA for your water.  TA buffers against PH drop. You most likely want to lower your TA down to the 50-70 range (uncorrected) so your PH will "lock" at a lower value.

Of course there could be other factors like extra aeration (leaving air jet features on or excessive filter cycles) that would cause increased PH.

I would suggest reading waterbear's post on lowering TA, as it has a ton of detailed information on this topic.

https://www.poolspaforum.com/forum/index.php?/topic/28846-lowering-total-alkalinity-howto/

Link to comment
Share on other sites

6 hours ago, JWM6687 said:

Again, I'm not the expert, but I believe corrected TA is only applicable when using the (Langelier) saturation index, which is not really applicable to acrylic hot tubs, and is used typically for pools (tiles, grout, gunite, etc.).

What is the uncorrected TA that you measured from the Taylor kit?  I'm thinking you are up at 80 or 90 ppm, which might be too high of a TA for your water.  TA buffers against PH drop. You most likely want to lower your TA down to the 50-70 range (uncorrected) so your PH will "lock" at a lower value.

Of course there could be other factors like extra aeration (leaving air jet features on or excessive filter cycles) that would cause increased PH.

I would suggest reading waterbear's post on lowering TA, as it has a ton of detailed information on this topic.

https://www.poolspaforum.com/forum/index.php?/topic/28846-lowering-total-alkalinity-howto/

Thanks JWM6687, I have read that post and it has proven helpful.  Uncorrected TA has been 60 and 70 depending on acid or baking soda additions.  You think I should be lower than that?

Link to comment
Share on other sites

Everyone's tub, water and treatment routines vary based on any number of factors.  It wouldn't hurt to try a lower TA around 40 or so to see if that lets your PH settle and "lock" in under 8.  When my TA gets down to 30 is when I see my PH really start dropping.  Your tub might not start dropping until 20, but that's for you to find out 😅.  TA buffers against PH drop, so maybe your water/chemical blend requires a lower TA buffer.  Also wouldn't hurt to double check filter cycles/duration/aeration that can raise PH.  Some further info you might find useful is this powerpoint from Bob Lowry that has a ton of info on PH buffers and borates.

https://cdn.ymaws.com/www.npconline.org/resource/resmgr/presentations/2020/Borates-Boric-Acid.pdf

TFP also has a wiki page on Borates you might find useful.

https://www.troublefreepool.com/wiki/index.php?title=Borates_in_pool

Just about everything I've learned on maintaining my tub comes for waterbear, chemgeek, and Lowry.  They are all an absolute wealth of knowledge.  Sometimes things are so complicated you need to have them explained three different ways to understand them 🙃.

  • Like 1
Link to comment
Share on other sites

1 hour ago, JWM6687 said:

Everyone's tub, water and treatment routines vary based on any number of factors.  It wouldn't hurt to try a lower TA around 40 or so to see if that lets your PH settle and "lock" in under 8.  When my TA gets down to 30 is when I see my PH really start dropping.  Your tub might not start dropping until 20, but that's for you to find out 😅.  TA buffers against PH drop, so maybe your water/chemical blend requires a lower TA buffer.  Also wouldn't hurt to double check filter cycles/duration/aeration that can raise PH.  Some further info you might find useful is this powerpoint from Bob Lowry that has a ton of info on PH buffers and borates.

https://cdn.ymaws.com/www.npconline.org/resource/resmgr/presentations/2020/Borates-Boric-Acid.pdf

TFP also has a wiki page on Borates you might find useful.

https://www.troublefreepool.com/wiki/index.php?title=Borates_in_pool

Just about everything I've learned on maintaining my tub comes for waterbear, chemgeek, and Lowry.  They are all an absolute wealth of knowledge.  Sometimes things are so complicated you need to have them explained three different ways to understand them 🙃.

I totally get it, thanks so much!

  • Like 1
Link to comment
Share on other sites

On 1/31/2023 at 3:55 PM, jaredthomas27 said:

pH is still hovering around 7.9-8.0  I have bumped my TA up to 88 with baking soda to give myself room to add more acid but I just added .5oz of acid and my pH remained unmoved.  Could that be because of the borates? 

1) do NOT correct the TA as outlined in the Taylor booklet. NOT necessary! @JWM6687  is correct, you only need to correct TA when calculaiting the Saturation Index and that is NOT applicable to acrylic tubs. If you have a plaster or tiled tub then you would need to worry about calcium and the saturation index.

2) if your pH remains stable and is not rising fast then your TA is fine. If it's rising fast then lower it. In most tubs this is between 50 and 70 ppm but it could even be lower in some situations. If your pH keeps crashing then your TA is too low, raise it 10 ppm and see how it goes.

3) the secondary borate buffer in the water will  move the pH to around 7.9 and keep it there for an extended period. You don't need to lower it until it rises above 8.0

4) you are making this much harder than it is. Stop overthinking and if it's not broke don't try to fix it. Get your TA in range and don't try to lower pH until it rises above 8.0. When you lower pH don't go below 7.6! If you are using the acid demand test to determine how much acid to add then trust the test and add the full amount, no need to try to ":creep up" to your desired pH by adding only half the amount. You are only prolonging your pain! ;)

5) read this, then reread it:

https://www.poolspaforum.com/forum/index.php?/topic/52522-some-truths-about-ph-and-ta/

Link to comment
Share on other sites

1 hour ago, waterbear said:

1) do NOT correct the TA as outlined in the Taylor booklet. NOT necessary! @JWM6687  is correct, you only need to correct TA when calculaiting the Saturation Index and that is NOT applicable to acrylic tubs. If you have a plaster or tiled tub then you would need to worry about calcium and the saturation index.

2) if your pH remains stable and is not rising fast then your TA is fine. If it's rising fast then lower it. In most tubs this is between 50 and 70 ppm but it could even be lower in some situations. If your pH keeps crashing then your TA is too low, raise it 10 ppm and see how it goes.

3) the secondary borate buffer in the water will  move the pH to around 7.9 and keep it there for an extended period. You don't need to lower it until it rises above 8.0

4) you are making this much harder than it is. Stop overthinking and if it's not broke don't try to fix it. Get your TA in range and don't try to lower pH until it rises above 8.0. When you lower pH don't go below 7.6! If you are using the acid demand test to determine how much acid to add then trust the test and add the full amount, no need to try to ":creep up" to your desired pH by adding only half the amount. You are only prolonging your pain! ;)

5) read this, then reread it:

https://www.poolspaforum.com/forum/index.php?/topic/52522-some-truths-about-ph-and-ta/

Thank you for the insight.  Yeah im definitely overthinking this.  Appreciate all the help and direction!

Link to comment
Share on other sites

Just remember, it's a hot tub, not a chemistry experiment! Go for a soak and enjoy! (Checking your sanitizer is MUCH more important than the pH or TA. An undersanitized tub can lead to all kinds of problems and possible illness.)

 

There, now you have something else to stress over! ;)

 

Link to comment
Share on other sites

On 2/6/2023 at 12:26 PM, waterbear said:

Just remember, it's a hot tub, not a chemistry experiment! Go for a soak and enjoy! (Checking your sanitizer is MUCH more important than the pH or TA. An undersanitized tub can lead to all kinds of problems and possible illness.)

 

There, now you have something else to stress over! ;)

 

Hahaha yeah my wife has been calling it my chemistry experiment, thats funny.  She knows my OCD makes me dive headfirst into this kind of stuff.  Jokes aside, I really appreciate you all's input, help, and plethora of information on this forum!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...