I'm thinking about buying boric acid from duda diesel, but I'm not sure if I should wait for my plaster to quit requiring so much MA. Is there a good reason to wait on taking the borates plunge with new plaster, or am I anticipating a problem that shouldn't occur? I'm thinking since I'm adding so much acid each day to compensate for the pH rise of the plaster, swg, and spa overflow, maybe adding borates would stop something that NEEDS to happen. Also, should I need to swing TA for some reason (My fill water is 110-120TA, so I usually make an effort to lower after adding water) I read that it's more difficult...is that overstated? How difficult is it?
Should I wait on adding borates to a new plaster pool?
- Thread starter gilbee
- Start date
- May 23, 2015
- 24,400
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
I think we've discussed your pool before. What's your current TA level and where do you target your pH? What CSI do you typically have?
I'm a huge fan of borates but I waited quite a while to pull trigger until my water chemistry was stable. Borates are not magical and they do add to the complexity of your water chemistry. You can still lower TA with borates in the water and borates do not change the fact that you'll still use the same amount of acid. You'll just be adding more acid with less frequency so the total acid volume used is the same.
Forgot to ask - how is your SWG doing with the new plaster? Any scaling? Is it staying clean?
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I'm a huge fan of borates but I waited quite a while to pull trigger until my water chemistry was stable. Borates are not magical and they do add to the complexity of your water chemistry. You can still lower TA with borates in the water and borates do not change the fact that you'll still use the same amount of acid. You'll just be adding more acid with less frequency so the total acid volume used is the same.
Forgot to ask - how is your SWG doing with the new plaster? Any scaling? Is it staying clean?
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TA is at 100, I attribute the rise to the filling of evaporated water we've all been having to do here in south Louisiana. I still target pH in the 7.6-7.8 neighborhood, but sometimes I will apply enough acid pull down to 7.3-7.4, knowing that within hours it will be in that 7.6-7.8 range that I seek. So my CSI will be typically no more than -.2 just after I've added acid in the mornings to almost perfect 0 during the day, and by late afternoon/evening pH rises again to bring me back to a pH of 8+ by the morning which puts my CSI back in the high positive (8.2 puts my CSI at .53).
pH stabilization would be nice, but I'm not expecting that with curing plaster....I was more thinking of doing the borates for the algaestatic properties and the comfort effects that it provides in the short run, with a long term of pH hold in the long run after the curing is over. Even holding off days between additions would be convenient...we went out of town for a couple of days and all I could think about was the pH going way out of sight without the daily additions that I normally make.
I've only had the SWG running for a month, so I haven't taken it down to check for scaling yet, I was gonna wait till the 2 or 3 month mark to inspect.
pH stabilization would be nice, but I'm not expecting that with curing plaster....I was more thinking of doing the borates for the algaestatic properties and the comfort effects that it provides in the short run, with a long term of pH hold in the long run after the curing is over. Even holding off days between additions would be convenient...we went out of town for a couple of days and all I could think about was the pH going way out of sight without the daily additions that I normally make.
I've only had the SWG running for a month, so I haven't taken it down to check for scaling yet, I was gonna wait till the 2 or 3 month mark to inspect.
- May 23, 2015
- 24,400
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Well, here's my advice - wait.
I know, not what you wanted to hear. But you've got two major variables that are still all over the place - a brand new SWG (which is most certainly pushing you pH up) and somewhat fresh plaster still curing (less than 1 year old). Those are both major contributors to your acid demand.
Honestly speaking, the subjective effects of borates (silky water feel and algae insurance) are very variable. Some folks see it right away and are like, "Wow! This water is awesome now," and others are like "Geez, why did I waste my money!" As far as algae prevention goes, it's more pronounced when the borate levels are 100ppm or higher, but that is not at all recommended for swimming pools. Yes, you do get some benefit from it at 50ppm, but it really is the FC doing the lion's share of the algae kill.
Would it be possible to get your TA down to 60ppm? If it were me, that would be my first step. Reduce your TA as far as you can. I have 120ppm TA fill water and I'm will to bet my dry climate produces more evaporative loss than yours. Yet I am able to routinely keep the TA at 60-70ppm. Would you be willing to try that first?
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I know, not what you wanted to hear. But you've got two major variables that are still all over the place - a brand new SWG (which is most certainly pushing you pH up) and somewhat fresh plaster still curing (less than 1 year old). Those are both major contributors to your acid demand.
Honestly speaking, the subjective effects of borates (silky water feel and algae insurance) are very variable. Some folks see it right away and are like, "Wow! This water is awesome now," and others are like "Geez, why did I waste my money!" As far as algae prevention goes, it's more pronounced when the borate levels are 100ppm or higher, but that is not at all recommended for swimming pools. Yes, you do get some benefit from it at 50ppm, but it really is the FC doing the lion's share of the algae kill.
Would it be possible to get your TA down to 60ppm? If it were me, that would be my first step. Reduce your TA as far as you can. I have 120ppm TA fill water and I'm will to bet my dry climate produces more evaporative loss than yours. Yet I am able to routinely keep the TA at 60-70ppm. Would you be willing to try that first?
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It's not really advice that I do or don't want to hear---I'm not hard over on adding the stuff honestly, and the ability to wait a few days between acid additions sounds nice, but I am cognizant that new plaster changes the game a bit for some of the rules here.
I'm sure I can get the TA down to 60...just a month ago I was at 70 as I was adding too much acid and basically doing the TA lowering technique when I added my daily dosages. I'm curious how important it is to get it down there though, since it seems to rise anyway on its own, and targeting 7.0-7.2 consistently to get it there puts the pool in a very negative CSI (7.0 would be -.62 at current TA, and only gets more negative as the TA lowers to a point where at say 70 a 7.0 pH would yield a -.81 in my pool all else equal) with I'm not sure what benefit (even when it was at 70 I still had to add the same amounts of acid daily)...I'm not saying I won't do it, I just like to appreciate why I'm doing things before I go down that path...help a brother out?
I'm sure I can get the TA down to 60...just a month ago I was at 70 as I was adding too much acid and basically doing the TA lowering technique when I added my daily dosages. I'm curious how important it is to get it down there though, since it seems to rise anyway on its own, and targeting 7.0-7.2 consistently to get it there puts the pool in a very negative CSI (7.0 would be -.62 at current TA, and only gets more negative as the TA lowers to a point where at say 70 a 7.0 pH would yield a -.81 in my pool all else equal) with I'm not sure what benefit (even when it was at 70 I still had to add the same amounts of acid daily)...I'm not saying I won't do it, I just like to appreciate why I'm doing things before I go down that path...help a brother out?
- May 23, 2015
- 24,400
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Well, it's the carbonate alkalinity that is driving your pH for the most part (along with plaster curing which also adds alkalinity too as the plaster converts calcium hydroxide to calcium carbonate). If 70ppm did not work then you could try to go down to 50ppm TA. Some people have gone as low as 40ppm, but you would have to increase your CH to compensate for the aggressive CSI. As for aggressive water at low pH, I don't think you have to worry about that a lot when lowering TA because the CSI doesn't really remain aggressive for very long. Your waters pH likely jumps from 7.2 to 7.5 very quickly (with 12-24 hours) and then more slowly from 7.6-8.0.
At the end of the day, I don't see any danger to adding borates to your pool. It will certainly help with the pH rise and where you want to be the most concerned is not the pH in your pool water but the pH rise in your SWG cell. The active plate in the SWG produces A LOT of hydrogen gas which makes the pH inside the cell very high (H2 gas has a fairly low solubility in water so most of that hydrogen off gasses from the water leaving you with a higher pH). So inside the cell, the pH can easily hit scaling levels. That is where the borates will do all of their work. Chemgeek did the analysis and I believe the borates cut down the pH rise inside the cell by over half.
My original suggestion to wait was just based on complexity. You've got a lot going in that pool (aside from the swimmers
) but it seems like you keep good logs of everything and you test a lot so you should be able to spot a problem well in advance of anything going sideways.My only suggestion would be this - get your pH and TA where you think you want it to be, then add the boric acid. The boric acid will drop your pH a bit (0.2-0.3 units depending on how much you add) and won't have much affect on TA (50ppm borates only adds about 5ppm to the TA measurement). So if you get your water where you want it to be in terms of pH, you should not have to adjust it much after adding the borates. Keep an eye on the FC too. When I added borates, I got a little bump in FC (perhaps due to an increase in cell efficiency or a lower algae/organic load). You might see that as well but not everyone does.
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I am a fan of borates for sure. I had 50ppm all last summer. With all the rain this spring it got diluted to to 20, I raised it back to 50 and the improvement was noticeable again. Nicer water, more PH stability, noticeable reduction in water bugs. I agree with lowering your TA first to 70ish or so. I agree that you are an experienced enough TFPer to manage your pool. The only real issue I have seen with borates is with high TA being more difficult to lower. But, I haven't had any real trouble lowering my TA with borates and you definitely understand the concept and the relationship with TA and PH. I say borates away!