Orenda Tech - Containing pH vs. Controlling pH

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zollan23

Well-known member
Oct 25, 2020
90
Southern California
Pool Size
13500
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-30
I'm curious if anyone has listened to this podcast or read through this article - Containing pH vs. Controlling pH in a Pool

It's an interesting read and while it does leverage the use of LSI, CSI could just as easily be used and the premise of the article would still hold water (see what I did there). The TL;DR version is this: As pool owners, we overuse acid and overwork ourselves by trying to keep pH within a tight range (for my pool, 7.6-7.8). Given pH's natural desire to go higher and water's need to be at equilibrium, instead of controlling the pH you contain it by using Alkalinity and Calcium to offset the LSI (in our case, CSI) to be in balance despite a "high" pH. So even at 8.0, your CSI can be within range, you're using less acid and because of how pH acts - it tends to rise exponentially slower as it reaches its natural ceiling - you can treat water with far less frequency.

I found it super interesting, especially as someone who has recently added Borates to my pool and still having issues with pH rising too often and adding acid (still unclear why my borates aren't working, as noted in this thread)

As a self-proclaimed newbie to all of this I would love to hear thoughts from the experts on this approach. The TFP method has not steered by wrong once so definitely curious. Love to always be learning.

Thanks,
 
To me the difference is keeping the pH at 7.8. if I were to do that, I would need to add acid every single day - and I have 60ppm of Borates. This seems to be saying, let it go and just contain it vs having it stay at 7.6-7.8.

Are you able to keep your pH at 7.8 for multiple days without acid treatment? Mine rises at least 0.1/day if not 0.2 some days.

I've never been able to get my TA to stay at 60 no matter how many times I do the acid/aeration.
 
zollan23 said:
To me the difference is keeping the pH at 7.8. if I were to do that, I would need to add acid every single day - and I have 60ppm of Borates. This seems to be saying, let it go and just contain it vs having it stay at 7.6-7.8.

Are you able to keep your pH at 7.8 for multiple days without acid treatment? Mine rises at least 0.1/day if not 0.2 some days.

I've never been able to get my TA to stay at 60 no matter how many times I do the acid/aeration.
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It’s not about keeping it at 7.8. It’s about keeping it between 7.0 and 7.9. That’s all the precision that TFP generally recommends. Once it gets to 8.0, the test results get harder to read.
 
Bperry said:
It’s not about keeping it at 7.8. It’s about keeping it between 7.0 and 7.9. That’s all the precision that TFP generally recommends. Once it gets to 8.0, the test results get harder to read.
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Fair enough. Let me ask this... Should I be prioritizing CSI? My pH is currently 8.0. If I dropped to 7.0, my CSI would be -0.58 which is outside the -0.30 - 0.30 range. All other readings being within reasonable ranges, am I right to want CSI range-bound above all else? It would essentially be identifying a pH floor/ceiling.

For example, my current levels across the board are within acceptable ranges. TA at 100 is high but otherwise, I'm good.

At pH of 7.3 my CSI would be -0.30 and at current 8.0 the CSI is 0.29. So, I could essentially now add enough acid to drop to 7.3 and be ok having it rise back to 8.0 and repeat... Yes?
 
zollan23 said:
At pH of 7.3 my CSI would be -0.30 and at current 8.0 the CSI is 0.29. So, I could essentially now add enough acid to drop to 7.3 and be ok having it rise back to 8.0 and repeat... Yes?
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Yes. In fact that would also tend to drop your TA and make the pH tend to rise slower. But the lower you drop the pH out of its “happy zone” the faster it will rise back. So unless you are specifically trying to drop the TA in a short period of time by acid dosing and aeration, just dose acid to get pH down to 7.6 or 7.8. That’s assuming you can accurately measure the difference between pH of 8.0 and 8.2 or above. Once mine gets to 8.2, I can’t tell if it’s 8.2 or 8.4 or 8.6 so I like to keep it in a range that my test kit can accurately measure.

As a related note, water temp is also a factor in that I had to add a lot of calcium once the temp starts getting down below 60’s to keep my CSI in a good range. My pH does not like staying below 7.8 and so I accommodate that and the lower water temperature with increased CH in the winter.

I also missed it somewhere but how old is your plaster? I’d read new plaster will always have fast rising pH for a time and it’s just something you have to deal with. Thought I’d mention that in case it was missed.
 
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Bperry said:
Yes. In fact that would also tend to drop your TA and make the pH tend to rise slower. But the lower you drop the pH out of its “happy zone” the faster it will rise back. So unless you are specifically trying to drop the TA in a short period of time by acid dosing and aeration, just dose acid to get pH down to 7.6 or 7.8. That’s assuming you can accurately measure the difference between pH of 8.0 and 8.2 or above. Once mine gets to 8.2, I can’t tell if it’s 8.2 or 8.4 or 8.6 so I like to keep it in a range that my test kit can accurately measure.

As a related note, water temp is also a factor in that I had to add a lot of calcium once the temp starts getting down below 60’s to keep my CSI in a good range. My pH does not like staying below 7.8 and so I accommodate that and the lower water temperature with increased CH in the winter.
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So this is my conundrum. If I only lower to 7.6, then I'm back adding acid every 3-4 days. The reason I wanted to add borates was to make that less frequent and that's not happening, and my goal is to be adding acid with less frequency (I understand the actual amount will not lessen).

At 100, I do need to lower my TA so this method will work, but for you, how often are you adding acid doing the lower to 7.6, rise to 8 method?

My pool is staying open with my heat pump, so temperature is a consistent 86.

Is the fact that plaster was put in only in July a factor? Like, should I expect this to be easier after a year or so?

Thanks
 

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zollan23 said:
So this is my conundrum. If I only lower to 7.6, then I'm back adding acid every 3-4 days. The reason I wanted to add borates was to make that less frequent and that's not happening, and my goal is to be adding acid with less frequency (I understand the actual amount will not lessen).

At 100, I do need to lower my TA so this method will work, but for you, how often are you adding acid doing the lower to 7.6, rise to 8 method?

My pool is staying open with my heat pump, so temperature is a consistent 86.

Is the fact that plaster was put in only in July a factor? Like, should I expect this to be easier after a year or so?

Thanks
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That’s likely the issue and should have caught that sooner. New plaster tends to have a very fast pH rise that will settle down over time. Just keep the pH in the 7’s as best you can. Someone else would have to comment on how long that takes, would guess it’s a year or so. As you are adding acid, the TA will naturally come down on its own and should help reduce acid demand as well.
 
The main problem with the Orenda method is that they push ignoring pH by attempting to control CH and TA. CH control is not easily managed unless you live back East where fill water is naturally soft or you engage in lots of draining and refill (where I live, water costs around $10/CCF). TA is primarily affected by fill water additions. Controlling TA and pH (they are linked) is easier in my opinion than trying to hold CH constant. Adding acid is far less costly than dumping water. If you have an SWG or heater, overall calcium levels do matter and should be kept within ranges and not allowed to drift too high because you cannot control the pH inside an SWG cell and heaters drive calcium out of solution. If you let CH get too high then you risk damaging equipment well before you will damage plaster.

A pool takes work, that’s a fact. You can minimize it some but a new pool takes lots of work. Adding acid every couple of days to a new pool is not at all unusual but it will get better. In the mean time, add a stenner acid dosing pump if lugging acid jugs bothers you. You can adjust the dosing frequency to match the TA rise and that will keep the pH fairly constant. You balance it out so that the pH sits around 7.8 and the amount of acid used will be fairly minimal, around a few ounces to one cup per day.
 
JoyfulNoise said:
The main problem with the Orenda method is that they push ignoring pH by attempting to control CH and TA. CH control is not easily managed unless you live back East where fill water is naturally soft or you engage in lots of draining and refill (where I live, water costs around $10/CCF). TA is primarily affected by fill water additions. Controlling TA and pH (they are linked) is easier in my opinion than trying to hold CH constant. Adding acid is far less costly than dumping water. If you have an SWG or heater, overall calcium levels do matter and should be kept within ranges and not allowed to drift too high because you cannot control the pH inside an SWG cell and heaters drive calcium out of solution. If you let CH get too high then you risk damaging equipment well before you will damage plaster.

A pool takes work, that’s a fact. You can minimize it some but a new pool takes lots of work. Adding acid every couple of days to a new pool is not at all unusual but it will get better. In the mean time, add a stenner acid dosing pump if lugging acid jugs bothers you. You can adjust the dosing frequency to match the TA rise and that will keep the pH fairly constant. You balance it out so that the pH sits around 7.8 and the amount of acid used will be fairly minimal, around a few ounces to one cup per day.
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Super helpful, thank you
 
Bperry said:
That’s likely the issue and should have caught that sooner. New plaster tends to have a very fast pH rise that will settle down over time. Just keep the pH in the 7’s as best you can. Someone else would have to comment on how long that takes, would guess it’s a year or so. As you are adding acid, the TA will naturally come down on its own and should help reduce acid demand as well.
Click to expand...
Thanks as well
 
ajw22 said:
What is the pH and TA of your fill water?
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Tested my water this morning. See below. I'm assuming that a fill TA of 150 is going to mean I'm always going to struggle with TA being higher than what I want (which is 70)?

It also has a screaming high pH which I was surprised by. It was a deep pink so I'm not even sure it's actual amount.

Thanks

[ ] FC - 0.50
[ ] CC - 1.5
[ ] CH - 200
[ ] TA - 150
[ ] pH - 8.5+
 
My fill water TA is 200. I am constantly having to address it. I have done the aeration/pH thing before and probably will this winter but mainly I just try to adjust pH to maintain CSI on the negative side. My TA is 150 right now and pH of 7.2 accomplishes that, (CH is 330).
 
Fill water with a TA of 150ppm will have an equilibrium pH of around 8.2-8.4. That means as you add it to your pool the increase in TA will always push your pH higher. There’s no (simple or cheap) way to reduce the TA in your fill water as that is a function of its source and the municipal water supplier. The only thing you have control over is minimizing evaporative loss as much as you can by controlling water features and/or using a pool cover.
 
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