Borates Impact on MA Demand

Stoopalini

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Jun 8, 2020
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Central Texas
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My pool is now 4 weeks filled, so I am planning to add salt and enable the IC40 this weekend. I am considering adding 50ppm Borates (using Boric Acid) for the added protection of the SWG cells, but also for the benefits of pH buffering and the aesthetic benefit of the water sparkle due to lower surface tension.

In researching this, I've been playing around with PoolMath, to see the impacts it will have on my routine maintenance. At this stage, my MA demand has really fallen when compared to the 1st couple of weeks. I assume this is due to the Pebblesheen plaster curing, but also due to my levels.

I'm now targeting 7.8 pH, and my TA has been slowly coming down with each MA addition. TA started at 160, and has been holding at 80 for about 2 weeks, but it just dropped to 70 with yesterday's MA addition. I assume the TA has been dropping a bit with each MA addition, but the test resolution of 10ppm prevents me from being able to see that. So as I continue to add MA to keep pH at 7.8, the TA will continue to drop, although more slowly, and eventually settle somewhere, hopefully above 50.

A thought I had on the Borates acting as an addition pH buffer is that if my TA continues to drop slowly over time, as I add MA to keep pH at 7.8, the Borates will help protect against a pH crash (if my TA get's down to 50 or less that is). Although maybe it won't, I'm not sure ....

So in thinking this through, one impact I'm noticing in PoolMath is the amount of MA needed to affect a pH change. With a TA of 70, and zero Borates ... I need 4.7oz of MA to lower my 14k pool's pH from 8.0 to 7.8. But with 50ppm of Borates, it requires 28oz of MA to lower the pH from 8.0 to 7.8. So 5.9x more MA for the same change.

I get this is because the Borates act as a pH buffer, so it takes more MA to result in the same change. My question has to do with the following:

If today, with zero Borates, by pool's pH rises from pH 7.8 to 8.0 over 1 week's time, and it then requires 4.7oz of MA to lower it back to 7.8 .... can I assume after adding 50ppm Borates, the same rise (with all else being equal) from 7.8 to 8.0 would now take about 6 weeks (28 / 4.7 = 5.9)? So my acid consumption doesn't really change, but instead of adding 4.7oz of MA once a week, over 6 weeks (~28oz total after 6 weeks) ... I would then do a one-time addition of 28oz of MA every 6 weeks?
 

Stoopalini

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Jun 8, 2020
442
Central Texas
Pool Size
14060
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
I can't really speak to the Borates as I don't use it due to cats drinking out of the pool.

What I want to address is the TA drops. You can add baking soda. Walmart has big bags of it. Here is the link to the recommended chemicals section: Recommended Pool Chemicals - Trouble Free Pool
Thanks Kim ... I was starting to wonder if I posted this in the wrong sub-forum maybe?

I understand baking soda can be used to raise TA, but the purpose of maintaining a TA greater than 50 is to have that pH buffer which results in a more stable pH and protection against a pH crash in the event of some influencing factor (acid rain, etc ...). But if the Borates also act as a strong pH buffer as much as I think they do, I shouldn't need to raise the TA and can avoid the baking soda regiment, right?

I believe the Borates will allow me to let the TA settle where it may, as well as reduce the frequency of MA additions. Therefore further reducing the amount of attention the pool will need on a regular basis.
 

JamesW

TFP Expert
Mar 2, 2011
21,536
It can help reduce the frequency of acid additions, but it's more complicated than it seems.

Borates offset some of the carbonate alkalinity, so you might need to increase the TA to compensate for the effect on the CSI.

As long as you keep the CSI between -0.3 and 0.0, the pH at 7.6 or higher and the TA low enough, the amount of acid required should be minimal.

Low CSI dissolves carbonate from the plaster, which raises the pH.
 

BenB

Gold Supporter
Jul 24, 2020
27
San Jose, CA
I'll just chip in as someone still learning all this stuff to say that as easy as the instructions seem to make adjustments to the pool, these aren't just levers we can pull on and magically will follow our directions and stay there. The water will "want" to return to some other state and we have to pick the battles worth fighting the hardest.

What I mean in your case is that you (like I did) wanted to hit the sweet spot on all of the measures, but for TA getting that nice and low might not be possible. Not least because of the amount of acid it would take as you pointed out!

Do you know the TA of your fill (tap) water? In my case, it's 100. So even if I could pull my TA down to the ideal level, there will always be constant weight on the scale pulling the TA back up towards 100 again. Day by day, drop by drop, it creeps up. So in the end I'm going to have to settle with a higher number and accept the things which we cannot meaningfully change :) Similarly, I wouldn't imagine there's any meaningful chance of a pH crash happening, so don't stock up on the bulk baking soda just yet!

Thank you for highlighting the difference in MA dosage though, I hadn't realized that at all after adding 30 borates. As a single data point, I have to add about 32oz of 31.45% every week to keep my pH down.
 

duraleigh

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TFP has always suggested that you get your pool really stable first and then educate yourself and decide on the use of borates. From posts above you can see the chemistry is not all black and white.

Feedback from those who have introduced borates to their pool range from "virtually no difference" to "This is the Second Coming!. It's pretty hard to be definitive with reports like that.

We have absolutely no reports of causing harm by adding borates but it is not something I would put in my pool.
 

jark87

Silver Supporter
Jun 5, 2011
267
Flower Mound, TX
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I gave borates a try several years ago in an attempt to control pH rise. As noted above, my experience was that it made no difference at all, but others reported that it helped them. It did give the water a different look though - like it had more surface tension, which I thought was kinda cool, but not enough so that I maintained borates.
 

Stoopalini

Gold Supporter
Jun 8, 2020
442
Central Texas
Pool Size
14060
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
It can help reduce the frequency of acid additions, but it's more complicated than it seems.

Borates offset some of the carbonate alkalinity, so you might need to increase the TA to compensate for the effect on the CSI.

As long as you keep the CSI between -0.3 and 0.0, the pH at 7.6 or higher and the TA low enough, the amount of acid required should be minimal.

Low CSI dissolves carbonate from the plaster, which raises the pH.
Ahhh, I see. I played around with PoolMath some more, and see what you mean by keeping the CSI in range. Although I thought -0.6 to +0.6 was 'ok', just according to what PoolMath is stating. But if I really need to keep it between -0.3 and 0.0, then ya, I need to rethink allowing the TA to settle so low (if it does in fact keep dropping).

The water will "want" to return to some other state and we have to pick the battles worth fighting the hardest.

What I mean in your case is that you (like I did) wanted to hit the sweet spot on all of the measures, but for TA getting that nice and low might not be possible. Not least because of the amount of acid it would take as you pointed out!
My idea isn't to target any particular TA number, but to allow it to naturally settle where it may, and make sure it results in good chemistry when it does. So my comment on TA isn't to try and lower it, or raise it ... but allow it to settle wherever it may. Based on my experience so far (granted, it's only been a month), the TA is continually dropping. It's gone from 160, down to 70 so far. And that's with my auto fill making up the water with 160 TA fill water.

Similarly, I wouldn't imagine there's any meaningful chance of a pH crash happening, so don't stock up on the bulk baking soda just yet!
Right, I'm not too worried about a pH crash ... but I was just pointing out the purpose (as I understand it) of the TA range, is to provide a buffer and protect against pH drift and crash. Seeing as Borates also buffer pH and protect against drift and a crash, it seems to me adding them would enable you to maintain a lower TA without increasing the risk. Again, not that I would intentionally add chemicals to to lower my TA, but would just allow it to settle wherever it may, and if that ends up being down at 50 or lower, then with the Borates, it wouldn't be a concern.

Although as James pointed out, it does kick the CSI below -0.3 ... so I need to rethink this if that's a problem.

Thank you for highlighting the difference in MA dosage though, I hadn't realized that at all after adding 30 borates. As a single data point, I have to add about 32oz of 31.45% every week to keep my pH down.
Sure thing ... you can just use the old PoolMath web tool to play around with Borate concentration, and see the impact it has on MA addition.

TFP has always suggested that you get your pool really stable first and then educate yourself and decide on the use of borates. From posts above you can see the chemistry is not all black and white.

Feedback from those who have introduced borates to their pool range from "virtually no difference" to "This is the Second Coming!. It's pretty hard to be definitive with reports like that.

We have absolutely no reports of causing harm by adding borates but it is not something I would put in my pool.
Thanks Dave. That's exactly my plan :) I've been testing quite frequently since the pool was filled 4 weeks ago (you can se my logs in my profile), and just today, I installed the IC40 and enabled it. So I wouldn't add Borates for a while (probably next summer, if I do), and I'll continue to educate myself in the meantime, and see how the water settles with the IC40. I get the winter months will also be very different than the summer months, so I'm hesitant to make any drastic changes.
 
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Stoopalini

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Jun 8, 2020
442
Central Texas
Pool Size
14060
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So I've been tracking my MA additions, and I know the SWCG isn't *supposed* to cause a faster rise in pH, but I can't help come to the conclusion that it has.

1601929965876.png

On Sep 16th, the last of my trichlor pucks dissolved, and I switched to only liquid chlorine. Then on Sep 26th, I installed the IC40.

I get with the trichlor pucks, the MA demand was kept in check due to them being acidic by nature. But even after the last of the pucks were dissolved, my pH still wasn't climbing too fast, and I only made 3 MA additions in 10 days. Now with the SWCG, it seems I need to make daily, or every 2 day, MA additions; as the pH is rising much faster than before.

Is this related to the IC40 directly, or should I be looking for something else, maybe related to the IC40 install procedure itself? Like maybe an air leak somewhere? Although I don't see any water leaks at the pad....

I do hear gurgling from time to time in the pipes, closer to the pool than the equipment pad. Maybe one of the o-rings (pump basket or IC40 unions) is letting air in?
 

JamesW

TFP Expert
Mar 2, 2011
21,536
My TA is pretty solid at 80. Sometimes it drops to 70, but not for long.
The TA has to be rising from something added to the water. That's what's increasing the pH. Keep the TA under control at about 60 ppm and the pH will be fine. The TA is not coming from the SWG. What is the fill water TA and how much fill water is added per week?
 

Stoopalini

Gold Supporter
Jun 8, 2020
442
Central Texas
Pool Size
14060
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
The TA has to be rising from something added to the water. That's what's increasing the pH. Keep the TA under control at about 60 ppm and the pH will be fine. The TA is not coming from the SWG. What is the fill water TA and how much fill water is added per week?
Fill water is high, 160ppm last time I measured it (back in June). But not much has been added lately ..... actually, none was added between late Sep and just a few days ago. The pool was up to the overflow during that time due to rain the week before. On Sat I noticed the water level was finally back down, and it was actually a bit below normal level; so I checked the Paralevel ... It wasn't running, so I gave the float a couple of taps with my finger, and then it started filling. I think some debris got caught in between the center support and the float.
 

Stoopalini

Gold Supporter
Jun 8, 2020
442
Central Texas
Pool Size
14060
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Whatever is raising the TA is raising the pH and it's not the SWG.
Not sure I follow. The TA is not rising, it's been at 80 for weeks. Every now and then, I'll record a 70 on the test, but it seems to always be somewhere between 70-80 ... it just depends how red the solution turns on the 7th drop and then if the 8th drops cause further color change or not. The 9th drop never causes more color change though.
 

Stoopalini

Gold Supporter
Jun 8, 2020
442
Central Texas
Pool Size
14060
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-40
Try keeping the TA at 60 and the CYA at 60 to 70.
Sure, I can do that.

What’s odd is the increase in MA demand with the same TA (80) and CYA (70) levels. The only difference is I installed the IC40 and stopped using liquid chlorine.