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I've read several articles on this forum and they've all been very, very educational and helpful. Unfortunately none of them have helped me figure out why I cannot achieve PH/TA balance. The only reason I'm posting this is because I have a feeling that it's something specific to the details of my setup. Hopefully the following details will help someone provide me some guidance as I've only owned this hot tub since July and I'm at the point of giving up on achieving PH/TA balance!

Let's set the baseline. This is a hot tub that was already installed at the house I purchased. It's a 350 gallon 2017 Marquis Hollywood Hot Tub. It seemed like it was in good condition when I got it, everything in tact and clean...still looked like new. It has a cover which is always on except when treating/testing or in use.

This is what I did (in order)

  1. Drained it
  2. Cleaned it
  3. Replaced the filter (factory)
  4. Installed a new UltraPure Ozonator, EUV3, UV, 115v/230v
  5. Filled the tub to 4" below the rim as the hot tub instructions stated
  6. Initial test of the water showed TA ~180, PH off the chart, and CH 220
    1. Tested using a Taylor K2005
      1. Confirmed Taylor accuracy with my local pool store test
  7. Added PH Decreaser 1oz, circulated 30 mins and repeated as needed until I got my PH to ~7.4
  8. Now my TA reads ~40 (It's low but I figured I'd see what happens after I performed the rest of the steps)
  9. Installed the Nature2 Spa Stick and followed it's instructions
    1. Added initial Dichlor shock
    2. Then use Oxy-Spa Non-chlorine Oxidizing Shock twice a week, or more, depending on usage
  10. Set the hot tub to 100 and it's always set there
  11. Set the filter to run twice a day for 3 hours at a time

**I've done the above twice, with the exception of replacing the ozonator, just to make sure I didn't biff something the first time...since it was my first time

As you can see, I'm not using Bromine or Chlorine, just the UltraPure Ozonator and the Nature 2 Spa Stick and my water seems to stay pretty clear for the most part. No strange odors or anything like that. I'm pretty sure that the Ozonator or Spa Stick don't have any influence on my initial balancing of the water as the Spa Stick isn't even in the tub yet when I start, but I thought I'd add ALL the details and see if there is something I'm just missing?

I've never, ever, ever been able to get both the PH and TA in balance simultaneously. I read others posts online and see them get it right and I've got balance envy now....which in turn makes me even more frustrated :) I hope that someone can help me understand where I'm failing! Thank you all in advance and Happy Holidays!

Nathan

Edited by nmiller0113
Changed the subject as my PH isn't really high, it's normal. It's my TA that's actually low.
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2 hours ago, RDspaguy said:

Keep your alk above 50 and your ph below 7.8 and you're set.

@waterbear, care to elaborate?

Thanks @RDspaguy, but I'm not sure that I can achieve that. I was at 34 two days ago with a PH of 7.8, which I also confirmed with my local pool supplier tests against my own.  Unless it's possible to make a small change that will only impact TA by 14 and not impact my PH of 7.8? I'm opening to any opinion :)

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  • nmiller0113 changed the title to Normal PH / Low TA

NO such thing as Normal pH/Low TA. If your pH is stable then your TA is fine! Period. A TA of 40 ppm is not unheard of in a spa, particularly with ozone which increases aeration and outgassing of CO2. IF your pH is fluctuating and not stable then your TA probably needs to raise SLIGHTLY! (50-60 ppm). Also, you are using MPS which is acidic and will cause both TA and pH to drop.

THE MAIN CAUSE OF pH RISE IN A POOL OR SPA IS OUTGASSING OF CO2.

THE HIGHER THE TA (CARBONATION IN THE WATER), THE FASTER CO2 WILL OUTGAS AND THE FASTER THE pH WILL RISE.

THE HIGHER THE AERATION OF THE WATER (OZONE SYSTEMS, SALT WATER SANITIZER SYSTEMS, AIR INJECTORS,  AERATION FROM YOUR JETS, 24 HOUR CIRCULATION ON HIGH SPEED, ETC.) THE FASTER CO2 WILL OUTGAS AND THE FASTER THE pH WILL RISE.

THE LOWER YOU PLACE THE pH THE FASTER IT WILL RISE (YOU ARE CONVERTING MORE BICARBONATE IONS, WHICH IS WHAT TA IS,  INTO CARBONIC ACID, ESSENTIALLY CO2 DISSOLVED IN THE WATER.

The proper way to lower TA is here, along with background info on why it works:

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

What you describes is not the best way to lower TA.

 

My concern is that you are using N2 with MPS and not chlorine. MPS is not a sanitizer, only an oxidizer. (There is some evidence that the combination of Ozone, MPS, and silver does have sanitizing properties in heated water commonly found in spas but there is no residual fast acting sanitizer in the water and the use of weekly chlorine shock is still recommended) The silver in the N2 cartridge is very slow acting and is ineffective against viruses and needs a fast acting sanitizer (chlorine).

Also, MPS is acidic and will cause both TA and pH to drop with use in addition to adding sufates to your water which can have a negative impact. Dichlor is also much more economical to use than MPS. I would suggest switching exclusively to dichlor for both after use and weekly shocking and maintaining a 1 ppm FC level since the .5 ppm recommended by zodiac provides no residual sanitizer in a hot tub because of the water to bather load ratio. The instruction manual for the N2 spa stick states:

"As an alternative to MPS, an EPA registered source of dichlor may be substituted: 1 tablespoon dichlor = approximately 3 tablespoons MPS."

Zodiac changed the instructions for N2 back around 2009 after it was determined that N2/MPS without weekly dichlor shock or ozone was ineffective at sanitizing pool and spa water and now only the spa system uses MPS along with dichlor but the pool system must use a chlorine source and not MPS. Prevously N2 was a non chlorine system for both pools and spas and only used MPS

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5 hours ago, waterbear said:

NO such thing as Normal pH/Low TA. If your pH is stable then your TA is fine! Period. A TA of 40 ppm is not unheard of in a spa, particularly with ozone which increases aeration and outgassing of CO2. IF your pH is fluctuating and not stable then your TA probably needs to raise SLIGHTLY! (50-60 ppm). Also, you are using MPS which is acidic and will cause both TA and pH to drop.

I believe I understand what you mean, I was only referring to "normal" based off of what is described in the Taylor test kit. I want to make sure I'm being clear on this, after I've drained and refilled my hot tub, before running anything or adding anything, including the N2 or any chemicals, my levels show around 180 TA and PH off the charts. Before  I add any MPS or Dichlor, only running the jets to mix (ozone is on by default) I cannot get my PH under 7.8 unless my TA is 40 or less. If I were to get my TA up to 50 my PH has always increased over 7.8. I'm re-stating this because you had mentioned other factors impacting it like MPS impacting TA. So I'm not sure how to keep my PH within range with my TA raised to 50 or 60. I've never been able to get it below 7.8 if my TA is that high. Is there something in my process that I'm failing at? I'm happy to change anything I'm doing.

5 hours ago, waterbear said:

The proper way to lower TA is here, along with background info on why it works:

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

What you describes is not the best way to lower TA.

I'm not sure I'm following this and it's likely just me misunderstanding. I'm not trying to lower my TA, I'm trying to lower my PH and keep my TA ~80. I understand that lowering PH impacts TA, but it doesn't seem I can ever get my PH below 7.8 without lowering my TA to 40 or less.

5 hours ago, waterbear said:

My concern is that you are using N2 with MPS and not chlorine. MPS is not a sanitizer, only an oxidizer. (There is some evidence that the combination of Ozone, MPS, and silver does have sanitizing properties in heated water commonly found in spas but there is no residual fast acting sanitizer in the water and the use of weekly chlorine shock is still recommended) The silver in the N2 cartridge is very slow acting and is ineffective against viruses and needs a fast acting sanitizer (chlorine).

Also, MPS is acidic and will cause both TA and pH to drop with use in addition to adding sufates to your water which can have a negative impact. Dichlor is also much more economical to use than MPS. I would suggest switching exclusively to dichlor for both after use and weekly shocking and maintaining a 1 ppm FC level since the .5 ppm recommended by zodiac provides no residual sanitizer in a hot tub because of the water to bather load ratio. The instruction manual for the N2 spa stick states:

"As an alternative to MPS, an EPA registered source of dichlor may be substituted: 1 tablespoon dichlor = approximately 3 tablespoons MPS."

Zodiac changed the instructions for N2 back around 2009 after it was determined that N2/MPS without weekly dichlor shock or ozone was ineffective at sanitizing pool and spa water and now only the spa system uses MPS along with dichlor but the pool system must use a chlorine source and not MPS. Prevously N2 was a non chlorine system for both pools and spas and only used MPS

As I mentioned above, I'm happy to change anything I'm doing. I based my process off a friends recommendation and some of my own reading. If you have posts on your recommendations on the best way to fill and maintain a hot tub, I'd be happy to read up...AND I'll start this whole this from scratch the right way...evening draining completely to start. I'd much rather do it exactly how you would. I don't need to be using the N2 or MPS. I'm no expert in this space and am all ears to following others guidance who know far more than I. I just want this to work and to be able to trust that 1) my family and I are safe to use this 2) I'm not damaging my hot tub and 3) I'm doing the way an expert would :) I appreciate all of your input @waterbear!

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I just found this article from Nitro, sounds like it may be what I'm looking for, but please let me know if you have any additional comments or supplemented info for it @waterbear. I'm also still interested in getting some clarification on my previous responses to better understand why even on a brand new fresh fill of water I still can't get my TA any higher than 40 without exceeding a PH of 7.8. If I haven't added any MPS at that point, is my ozonator the cause of my PH raising to a point where I can't get my TA above 40? Do I need to remove my ozonator and just follow Nitro's guide? Thanks again in advance!

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First I will address your issues then comment on Nitro's write up since I knew him from another forum where I used to be a moderator that was a swimming pool forum and where he got most of his information. However, it was not optimized for hot tubs but rather for plaster surface pools, which are a different animal.

First question, did you read the link I posted? It explain not only how to lower TA but WHY it rises. Please read it if you have not and if you have read it again. I t will answer a lot of your questions.

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

15 hours ago, nmiller0113 said:

I'm trying to lower my PH and keep my TA ~80. I understand that lowering PH impacts TA, but it doesn't seem I can ever get my PH below 7.8 without lowering my TA to 40 or less

Because of the amount of aeration in your spa it could very well be impossible to keep your pH in line with a TA over 40 ppm. Don't lose sleep over it. Why do you feel you need to keep your TA at 80 ppm? Because the Taylor kit said so? Because Nitro said so? The limiting factor is pH stability. If your pH is rising and stays too high then your TA is too high. Period! If a TA of 40 is your sweet spot then keep the TA at 40 if it drop lower (because of MPS and dichlor since both are acidic) then raise it back to 40 ppm. Easy Peasy!

 

How quickly does your pH rise above 7.8 if the TA is at 50 ppm or 60 ppm (hot tubs usually need to keep the TA at 40-60 ppm for pH stability, btw and pools using inorganic chlorine sources such as liquid chlorine, SWG, or cal hypo usually need a TA of 50-70 ppm. How low are you dropping your pH? You might find that if you try to keep your pH around 7.6 to 7.7 and not try to lower it until it rises ABOVE 7.8 then your pH is much more stable. Also adding borate at 30-50 ppm will introduce a secondary pH buffer that increases pH stability and your pH will happily sit at around 7.7 for an extended period of time compared to a tub or pool without borate. There are many commercial borate products (such as Proteam Gentle Spa) but you can achieve the same results with either 20 Mule Team Borax and acid to offset the pH rise from the alkaline borax or by using boric acid (a bit more expensive but still cheaper than the commercial products) will will cause a very slight pH drop when initially added. Once added all forms of borate form a secondary borate/boric acid pH buffer that compliments the bicarbonate/carbonic acid pH buffer system we create by adding sodium bicarbonate (pH inceaser) to the water when TA is too low that tends to cause pH to drop as opposed to rise.

I run my pool and attached spill over spa at 50-60 ppm with ppm borate since my spa had an air pump and air injectors and I have several water features such as deck jets and spillovers and 2 waterfall fountains as well as a SWG that also increases aeration. I only have to add acid about every 6 to 8 weeks. My point is you want to set it low enough to minimize pH rise but YOU CANNOT ELIMINATE pH RISE.

 

15 hours ago, nmiller0113 said:

I based my process off a friends recommendation and some of my own reading.

Every hot tub is different and unique and had to be looked at individually. What works for your friend might not work for you even if the tubs are identical . However, there are guidelines based on chemistry that you can apply to your situation to improve it. I will ask again, how fast does your pH rise when your TA is above 40 ppm but no higher than 60 ppm? a few hours, a few days? You cannot expect a hot tub with ozone to keep the pH stable for more than a week in many cases, particularly if you are trying to maintain a TA above 60 ppm and in many cases above 40 ppm. IF you cannot get a week of pH stability then I would strongly recommend the addition of borate.

 

15 hours ago, nmiller0113 said:

after I've drained and refilled my hot tub, before running anything or adding anything, including the N2 or any chemicals, my levels show around 180 TA and PH off the charts.

Very simple, first thing to do is get the TA down to 40-60 ppm following the instructions in the link I provided above. Then continue to balance your water. You only need to add calcium if yours is below about 130 ppm unless you have a plaster surface spa. CH can help prevent foaming that happens when the water is too soft in an acrylic spa but is not necessary at higher levels like it is in a plaster surface pool which is what Nitro erroneously based his water balance recommendations on. Wnile there is a lot of good information in his post there is also a lot of misinformation. The post of his to follow is the Dichlor/Bleach Method in a Nutshell post if you want to go that route.

Also, THIS post has more information on TA and pH. Read it.

https://www.poolspaforum.com/forum/index.php?/topic/6603-low-ph-high-ta-high-cya-chlorine-not-holding/&do=findComment&comment=27616

15 hours ago, nmiller0113 said:

is my ozonator the cause of my PH raising to a point where I can't get my TA above 40? Do I need to remove my ozonator and just follow Nitro's guide?

Most likely yes to your first question. Answer is to keep your TA at 40 ppm and monitor it weekly (which is standard practice anyway) and when it drops lower because of your MPS/dichlor use bring the TA back up to 40. If you overshoot and it hits 50 or even 60 it just means your pH wil rise faster. Don't worry about lowering the TA in that case, just check pH daily (also normal practice) and lower it to 7.6 (but not any lower) when it is ABOVE 7.8. The TA will eventually come down beuase of your use of MPS. IF yuo continue to use the N2 the main change I would make is to shock weekly with dichlor instead of as needed or use dichlor instead of MPS after each soak and maintian .5 to 1 ppm. I would shoot for 1 ppm. You can also ditch the N2 and use the dichlor/bleach method which Nitro wrote up but was really created by chem geek based on the chemistry of chlorine and CYA. Bottom line, it works!

As for your second question, no you don't need to remove your ozonator, just realize that it is an aeration source and that you will have to compensate for the extra aeration by running a slightly lower TA. Also, as I said before Nitro based much of his guide from info in a different forum (when I was a moderator there) and the info was not geared to spas but rather to plaster surface pools. While there is much good information in his guide there are also some recommendations that are not really correct such as his statement that CH is used to determine TA and pH levels. chem geek's replies in the thread are well worth reading, however.

Hope this clears some things up for you.

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@waterbearThank you so much for the details I really really appreciate the education and all that I've learned here from your and others like @chem geek posts. Sorry for the delayed response, the holidays had me distracted.

On 12/26/2020 at 6:59 AM, waterbear said:

First I will address your issues then comment on Nitro's write up since I knew him from another forum where I used to be a moderator that was a swimming pool forum and where he got most of his information. However, it was not optimized for hot tubs but rather for plaster surface pools, which are a different animal.

First question, did you read the link I posted? It explain not only how to lower TA but WHY it rises. Please read it if you have not and if you have read it again. I t will answer a lot of your questions.

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

Because of the amount of aeration in your spa it could very well be impossible to keep your pH in line with a TA over 40 ppm. Don't lose sleep over it. Why do you feel you need to keep your TA at 80 ppm? Because the Taylor kit said so? Because Nitro said so? The limiting factor is pH stability. If your pH is rising and stays too high then your TA is too high. Period! If a TA of 40 is your sweet spot then keep the TA at 40 if it drop lower (because of MPS and dichlor since both are acidic) then raise it back to 40 ppm. Easy Peasy!

How quickly does your pH rise above 7.8 if the TA is at 50 ppm or 60 ppm (hot tubs usually need to keep the TA at 40-60 ppm for pH stability, btw and pools using inorganic chlorine sources such as liquid chlorine, SWG, or cal hypo usually need a TA of 50-70 ppm. How low are you dropping your pH? You might find that if you try to keep your pH around 7.6 to 7.7 and not try to lower it until it rises ABOVE 7.8 then your pH is much more stable.

Yes, I read your post and was only confused because it's very clear on how to lower TA (and pH) incrementally and raise pH (independently) up through aeration, but my problem has never been with high TA. As you mentioned, I targeted a TA of 80 based on what I read in the Taylor Kit. I thought that was what I needed to be at, but as your post states, there is no way to independently raise TA without raising pH, only a way to raise pH without raising TA (aeration). So I was trying to accomplish the impossible in getting my TA ~80 when my starting point on a fresh refill without any aeration is a very high pH (above the measurable level with my kit) and about 180 TA. When I lower my TA to 80 my pH is ~8.0. To answer your question "How quickly does your pH rise above 7.8 if the TA is at 50 ppm or 60 ppm", it's immediate. Right now my TA is 40. If I raise it to 50 my pH immediately moves to somewhere over 7.8...I don't know the exact number as I'm using the Taylor Kit so I only have color shades, but it's definitely darker than 7.8. I'm curious if I'm missing something as you asking about how quickly pH rises above 7.8 makes me think you're stating that the pH shouldn't be above 7.8 to start when my TA is at 50 ppm. I can't even get my pH lower than 7.8 on a fresh fill of water, with nothing running or chemicals added, until I get my TA to 40...anything above that and my pH is still greater than 7.8. As for my pH stability overall, I don't think it is moving too quickly any direction and seems to stay fairly stable, even with the TA at 40.

The parts from your response that I'm keying in on is pH stability and whatever achieves that sweet spot is where I want to keep my TA...as you say "Easy Peasy" :) So that's what I'll focus on rather than achieving the TA the Taylor Kit says I should be at, whatever achieves pH stability in the right pH range ~7.6. I hope I'm understanding that correctly, because I just wonder that if TA at 40 didn't provide any pH stability, then what would I do since I cannot raise TA any higher? I guess I could just go lower, since higher would exceed a pH of 7.8, but I'm mainly asking that last question to re-affirm whether I'm understanding your points.

On 12/26/2020 at 6:59 AM, waterbear said:

Also adding borate at 30-50 ppm will introduce a secondary pH buffer that increases pH stability and your pH will happily sit at around 7.7 for an extended period of time compared to a tub or pool without borate. There are many commercial borate products (such as Proteam Gentle Spa) but you can achieve the same results with either 20 Mule Team Borax and acid to offset the pH rise from the alkaline borax or by using boric acid (a bit more expensive but still cheaper than the commercial products) will will cause a very slight pH drop when initially added. Once added all forms of borate form a secondary borate/boric acid pH buffer that compliments the bicarbonate/carbonic acid pH buffer system we create by adding sodium bicarbonate (pH inceaser) to the water when TA is too low that tends to cause pH to drop as opposed to rise.

You mentioned adding 30-50ppm of borate, how often do you recommend I do that to maintain a certain borate ppm? Is there a way to measure that, or is it just based on use?

On 12/26/2020 at 6:59 AM, waterbear said:

Very simple, first thing to do is get the TA down to 40-60 ppm following the instructions in the link I provided above. Then continue to balance your water. You only need to add calcium if yours is below about 130 ppm unless you have a plaster surface spa.

CH seems to be good on a fresh fill so I'm happy not to have to mess with that at all. With that said, I've seen others post that mention using a filter on the hose for the initial fill. Do you suggest that or does this not really impact my problem areas at all? I'm assuming it doesn't so I won't get one unless you think it's a good idea and would provide some value.

 

On 12/26/2020 at 6:59 AM, waterbear said:

The post of his to follow is the Dichlor/Bleach Method in a Nutshell post if you want to go that route.

Also, THIS post has more information on TA and pH. Read it.

https://www.poolspaforum.com/forum/index.php?/topic/6603-low-ph-high-ta-high-cya-chlorine-not-holding/&do=findComment&comment=27616

Most likely yes to your first question. Answer is to keep your TA at 40 ppm and monitor it weekly (which is standard practice anyway) and when it drops lower because of your MPS/dichlor use bring the TA back up to 40. If you overshoot and it hits 50 or even 60 it just means your pH wil rise faster. Don't worry about lowering the TA in that case, just check pH daily (also normal practice) and lower it to 7.6 (but not any lower) when it is ABOVE 7.8. The TA will eventually come down beuase of your use of MPS. IF yuo continue to use the N2 the main change I would make is to shock weekly with dichlor instead of as needed or use dichlor instead of MPS after each soak and maintian .5 to 1 ppm. I would shoot for 1 ppm. You can also ditch the N2 and use the dichlor/bleach method which Nitro wrote up but was really created by chem geek based on the chemistry of chlorine and CYA. Bottom line, it works!

I'm going to follow the Dichlor/Bleach Method in a Nutshell post and do away with the use of N2 and MPS. I feel like it will do a better job of achieving and maintaining my sanitation goals. Though I've got some questions following his post as it says read links below, but there aren't any links that I could see.

  1. What should I target to maintain in FC? Is 3-6ppm correct? It says that in Nitro's other post, it also mentions shocking to 12ppm FC once a week but not in the Nutshell post. Is that no necessary? I read Nitro's CD post which, if I'm understanding it correctly, answers this question for me as it's really based on my use/needs...but if you've got any additional guidance I'm all ears.
  2. Nitro mentions using MPS for high bather loads to help chlorine. How much should I be adding?
  3. Nitro mentions checking CYA every 3 months. Is the goal to get it back to 30 ppm CYA every 3 months?
On 12/26/2020 at 6:59 AM, waterbear said:

As for your second question, no you don't need to remove your ozonator, just realize that it is an aeration source and that you will have to compensate for the extra aeration by running a slightly lower TA. Also, as I said before Nitro based much of his guide from info in a different forum (when I was a moderator there) and the info was not geared to spas but rather to plaster surface pools. While there is much good information in his guide there are also some recommendations that are not really correct such as his statement that CH is used to determine TA and pH levels. chem geek's replies in the thread are well worth reading, however.

Hope this clears some things up for you.

Yes, this post has helped A LOT and cleared a lot of things up, but I'm sorry that it also made me ask more questions :) Regarding overall aeration, my final question is if I'm using the Dichlor/Bleach method, how long would you recommend running the filter system in total in a 24 hour period? Mine runs every 12 hours automatically and I can define how long it runs each time. I am currently running it for 3 hours every 12 hours (6 hours total/24 hour period) for more ozonator effectiveness, but can raise or lower per your suggestion.

Thank you again for everything!

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@waterbear Happy New Year! I was just looking back to see if there were any updates to my last questions as I’m working on cleaning and refilling tomorrow to start from scratch. I didn’t know if you had seen my last response so I’m just checking to confirm. I assume though that you’ve probably seen it and just been too busy to respond since I asked a lot more questions. Either way, thank you again and I hope you’re new year is starting off well!

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On 12/28/2020 at 3:14 PM, nmiller0113 said:

Yes, I read your post and was only confused because it's very clear on how to lower TA (and pH) incrementally and raise pH (independently) up through aeration, but my problem has never been with high TA.

IF your pH is rising fast then your problem is high TA. Period!

On 12/28/2020 at 3:14 PM, nmiller0113 said:

So I was trying to accomplish the impossible in getting my TA ~80 when my starting point on a fresh refill without any aeration is a very high pH (above the measurable level with my kit) and about 180 TA.

First step on fresh fill, use the acid demand test in your Taylor kit to see how much acid you need to add to lower your pH to 7.6 and do that. Check TA and then follow the steps to lower TA. Once TA is on target use the acid demand test to lower the pH to 7.6 if it's too high and check TA to see where it is (it probably won't change since it takes a lot more acid to lower TA than to lower pH). You can shoot for a TA of 40 ppm but I suspect that a slightly higher TA would also work if you do it this way.

On 12/28/2020 at 3:14 PM, nmiller0113 said:

If I raise it to 50 my pH immediately moves to somewhere over 7.8

and your next step is to use the acid demand test to lower the pH to 7.6. You will find that pH will drop but TA will be unchanged. Raising TA involved adding baking soda (which is what TA increaser is) and that will also raise pH. Just lower the pH and you are golden.

You are overthinking this. Acid will lower both pH and TA but it takes a LOT more acid to lower TA than pH. Adding baking soda will raise both TA and pH but it will raise TA more. Adding enough acid to lower the pH will have no or mimimal impact on TA. Adding washing soda (sodium carbonate AKA pH increaser) willo raise both pH an TA but it causes TA to rise quite a bit. This is only useful when running very acidic sanitizers like trichor, which require a much higher TA to prevent pH crash. This will not apply to you.

On 12/28/2020 at 3:14 PM, nmiller0113 said:

You mentioned adding 30-50ppm of borate, how often do you recommend I do that to maintain a certain borate ppm? Is there a way to measure that, or is it just based on use?

once your initial dose is added you will only lose borate by splashout or water changes. To test I recommend the LaMotte borate test strips, they are much easier to read than the Aquachek, Taylor, or Hach borate test strips which have colors in different shades of tan that are very close. The LaMotte strips have a color change from tan to pink to deep rose.  My recommendation is to add enough borate product (and acid if your product causes pH rise) to reach 50 ppm and monitor weekly to monthly and when it  drops to 30 ppm add enough to raise it back to 50 ppm. IF you go with boric acid you will need approx 4 oz for every 100 gallons of water to get approx. 50 ppm from zero (close enough) and every .5 oz will raise 100 gallons about 5 ppm. Boric acid will slightly lower pH so it is probably the best choice for you. If you want to use 20 mule team borax you will need about 6 oz by weight on a fresh fill for every 100 gallons and also need to add acid to lower the pH since it will bring the pH very high. I would add it in 3 separate doses that are dissolved in a bucket of water, circulate for about 20 min to mix, do an acid demand test to determine how much acid to add to lower the pH to 7.2 - 7.6 (or a bit lower in this case is fine), circulate again to mix and repeat until your full dose of borax has been added. If you are using a commercial borfate product follow the instructions on dosing and acid (if it is not a pH neutral product) and use your test strips to determine borate level and make adjustments accordingly to achieve 30-50 ppm.

 

On 12/28/2020 at 3:14 PM, nmiller0113 said:

I've seen others post that mention using a filter on the hose for the initial fill. Do you suggest that or does this not really impact my problem areas at all?

Prefilters filter out Iron, no Calcium If you don't have iron (usually from well water) and your water does not turn brown from the formation of iron oxide (rust) when you shock and you don't have rust stains in the tub (or in your toilets and sinks) then you don'd need one. The only way to REMOVE calcium is by using an ion exchange  device that replaces the calcium ions in the water with either sodium or potassium. These are called water softeners (only the ones that use salt or potassium chloride will work. The so called saltless softeners do NOT remove calcium, only change the scale produce from calcite (very hard crystal) to aragonite (softer crystals that don't build up in pipes and on surfaces) . If you want to fill with softened water from a salt based water softener that is OK but you might need to add some calcium after since it might be too low. Calcium makes water hard and helps prevent foaming if it is around 120 to 140 ppm. Higher is not necessary in most cases.

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On 12/28/2020 at 3:14 PM, nmiller0113 said:
  • What should I target to maintain in FC? Is 3-6ppm correct? It says that in Nitro's other post, it also mentions shocking to 12ppm FC once a week but not in the Nutshell post. Is that no necessary? I read Nitro's CD post which, if I'm understanding it correctly, answers this question for me as it's really based on my use/needs...but if you've got any additional guidance I'm all ears.
  • Nitro mentions using MPS for high bather loads to help chlorine. How much should I be adding?
  • Nitro mentions checking CYA every 3 months. Is the goal to get it back to 30 ppm CYA every 3 months?

3-6 ppm for a CYA of 20-30 ppm, shock when combined chlorine is ABOVE .5 ppm. Depending on spa use this could be weekly or more or less.

MPS is only necessary if combined chlorine cannot be lowered below 1 ppm by shocking. Should not be necessary if you are using ozone.

I would check CYA monthly. You will lose CYA (and borate) by splashout and water that is lost on bathing suits. Because of the small amount of water in a tub compared to a pool this can happen faster than you expect. When CYA drops you will want to switch to dichlor until it's back up. An easy rule of thumb is that for every 10 ppm chlorine added by dichlor you are adding 9 ppm CYA. This effect is cumulative so if you have to raise your FC by 2 ppm, then the next time by2ppm then you add 6 ppm to shock you have added a total of 10 ppm chlorine and 9 ppm CYA to the water.

On 12/28/2020 at 3:14 PM, nmiller0113 said:

Regarding overall aeration, my final question is if I'm using the Dichlor/Bleach method, how long would you recommend running the filter system in total in a 24 hour period?

NO hard and fast rules here. If the tub is stable the a total of 6 hours is fine. If you are having pH stability issues cause by aeration try dropping the total time to 4 hours. If the water has problems then increase the time. It's really trial and error. I would start with the recommended time and adjust down or up from there. but I would not go under 4 hours total time.

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2 hours ago, waterbear said:

IF your pH is rising fast then your problem is high TA. Period!

First step on fresh fill, use the acid demand test in your Taylor kit to see how much acid you need to add to lower your pH to 7.6 and do that. Check TA and then follow the steps to lower TA. Once TA is on target use the acid demand test to lower the pH to 7.6 if it's too high and check TA to see where it is (it probably won't change since it takes a lot more acid to lower TA than to lower pH). You can shoot for a TA of 40 ppm but I suspect that a slightly higher TA would also work if you do it this way.

and your next step is to use the acid demand test to lower the pH to 7.6. You will find that pH will drop but TA will be unchanged. Raising TA involved adding baking soda (which is what TA increaser is) and that will also raise pH. Just lower the pH and you are golden.

You are overthinking this. Acid will lower both pH and TA but it takes a LOT more acid to lower TA than pH. Adding baking soda will raise both TA and pH but it will raise TA more. Adding enough acid to lower the pH will have no or mimimal impact on TA. Adding washing soda (sodium carbonate AKA pH increaser) willo raise both pH an TA but it causes TA to rise quite a bit. This is only useful when running very acidic sanitizers like trichor, which require a much higher TA to prevent pH crash. This will not apply to you.

I most definitely am overthinking it, I've also not been using the Acid Demand test to get exact amounts and just basing it on the doses mentioned on the chemicals I've purchased. Maybe that's why I've been yoyo'ing. You mention lowering TA after getting to 7.6 pH to reach a target TA. What is the target, or would I not know that until I see how my pH behaves after some time and I find the sweet spot? What if my TA is 40 to 50 following the lowering of pH with Acid?

Quote

once your initial dose is added you will only lose borate by splashout or water changes. To test I recommend the LaMotte borate test strips, they are much easier to read than the Aquachek, Taylor, or Hach borate test strips which have colors in different shades of tan that are very close. The LaMotte strips have a color change from tan to pink to deep rose.  My recommendation is to add enough borate product (and acid if your product causes pH rise) to reach 50 ppm and monitor weekly to monthly and when it  drops to 30 ppm add enough to raise it back to 50 ppm. IF you go with boric acid you will need approx 4 oz for every 100 gallons of water to get approx. 50 ppm from zero (close enough) and every .5 oz will raise 100 gallons about 5 ppm. Boric acid will slightly lower pH so it is probably the best choice for you. If you want to use 20 mule team borax you will need about 6 oz by weight on a fresh fill for every 100 gallons and also need to add acid to lower the pH since it will bring the pH very high. I would add it in 3 separate doses that are dissolved in a bucket of water, circulate for about 20 min to mix, do an acid demand test to determine how much acid to add to lower the pH to 7.2 - 7.6 (or a bit lower in this case is fine), circulate again to mix and repeat until your full dose of borax has been added. If you are using a commercial borfate product follow the instructions on dosing and acid (if it is not a pH neutral product) and use your test strips to determine borate level and make adjustments accordingly to achieve 30-50 ppm.

Thank you, I ordered some boric acid from Duda Energy and also ordered some LaMotte borate test strips

Quote

Prefilters filter out Iron, no Calcium If you don't have iron (usually from well water) and your water does not turn brown from the formation of iron oxide (rust) when you shock and you don't have rust stains in the tub (or in your toilets and sinks) then you don'd need one. The only way to REMOVE calcium is by using an ion exchange  device that replaces the calcium ions in the water with either sodium or potassium. These are called water softeners (only the ones that use salt or potassium chloride will work. The so called saltless softeners do NOT remove calcium, only change the scale produce from calcite (very hard crystal) to aragonite (softer crystals that don't build up in pipes and on surfaces) . If you want to fill with softened water from a salt based water softener that is OK but you might need to add some calcium after since it might be too low. Calcium makes water hard and helps prevent foaming if it is around 120 to 140 ppm. Higher is not necessary in most cases.

It doesn't seem like I need this then, thank you!

1 hour ago, waterbear said:

3-6 ppm for a CYA of 20-30 ppm, shock when combined chlorine is ABOVE .5 ppm. Depending on spa use this could be weekly or more or less.

MPS is only necessary if combined chlorine cannot be lowered below 1 ppm by shocking. Should not be necessary if you are using ozone.

I would check CYA monthly. You will lose CYA (and borate) by splashout and water that is lost on bathing suits. Because of the small amount of water in a tub compared to a pool this can happen faster than you expect. When CYA drops you will want to switch to dichlor until it's back up. An easy rule of thumb is that for every 10 ppm chlorine added by dichlor you are adding 9 ppm CYA. This effect is cumulative so if you have to raise your FC by 2 ppm, then the next time by2ppm then you add 6 ppm to shock you have added a total of 10 ppm chlorine and 9 ppm CYA to the water.

Got it, I'll be sure to test for combined chlorine. Is there a calculator to determine how much bleach I'll need to add to move my combined chlorine below .5 and is there a too low number for this?

I'm also a bit confused on maintaining 3-6 FC ppm vs shocking. I've been recommended to use standard pool chlorine vs. the Clorox 6% unscented bleach since it's hard to come by, but this is called shock right on the label...though they're recommending it in place of the bleach to maintain a 3-6 FC ppm...and in Nitro's other post the only difference I see in "shocking" is he mentions raising the ppm to 12 once a week. It seems like "shocking" has different meanings based on the post perspective. I'm hoping you can provide some clarity on this? Also, do you think the standard pool chlorine is the right choice as it seems to be a higher concentrate so I'd need to know what to select in the pool calculator. Maybe you use something different?

Quote

NO hard and fast rules here. If the tub is stable the a total of 6 hours is fine. If you are having pH stability issues cause by aeration try dropping the total time to 4 hours. If the water has problems then increase the time. It's really trial and error. I would start with the recommended time and adjust down or up from there. but I would not go under 4 hours total time.

Ok, great...I'll start with 4 and see how it goes.

Thank you so much again @waterbear, far less questions this round and I feel like I'm finally starting to wrap my head around all of this...at least at a basic level.

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2 minutes ago, nmiller0113 said:

What is the target,

Since you have not been doing it right I would start with a TA of 60 ppm. If your pH rises too fast and you need to add acid more than once a week to keep it in line then I would try 50 and see. If not, then try 40.

Also once you add the borate (do so AFTER TA is on target) you will find that your pH is more stable as long as you keep the TA in the 40-60 ppm range and DO NOT LOWER THE pH BELOW 7.6 unless you are trying to lower the TA. Borate will possibly raise your TA reading since you are really just titrating the total alkalinity present but it is NOT carbonate alkalinity so it will not cause pH to rise. In fact the boric acid/borate buffer tends to make pH drift downward. You will find that the sweet spot for pH is right around 7.7 and I would not worry about lowering it until it rises ABOVE 7.8 when you should drop it to 7.6 and not lower. Once you have gone through this process you will learn the approx. amount of acid needed to lower your pH each time for your chosen TA and borate levels, which makes things much easier.

 

11 minutes ago, nmiller0113 said:

I've been recommended to use standard pool chlorine vs. the Clorox 6% unscented bleach since it's hard to come by

Bleach is normally easy to find but Covid 19 has made it more difficult. Only difference is the concentration, with laundry bleach being 5.25% or 6% and pool chlorine being 10% or 12.5%. FWIW, Pool chlorine is normally referred to as bleach by pool professinals! ;)

 

14 minutes ago, nmiller0113 said:

It seems like "shocking" has different meanings based on the post perspective

Common misconception. Shock is a verb. It means raising the sanitizer level high enough to destroy CC or algae and the level needed depends on what you are trying to do AND the current CYA level. For example, in a plaster pool with CYA in the 30-50 ppm range with black algae normally need to be 'nuked' to a FC level of 50 ppm or higher and maintained there for a period of time to kill the black algae. An acrylic spa with a CYA level of 30 ppm needs a shock of 12 ppm to destroy CC. There is no such thing as product named "shock" They will either be a standard chlorine source such as cal hypo, lithium hypo , liquid chlorine, dichlor, or a non chlorine oxidizer such as MPS. Some chloirne sources also include algacides and or clarifiers, which are totally unnecessary in most cases since chlorine is the best algaecide around.

I use PoolMath (search for it on Google). This is the original pool calculator written by JasonLion from TFP and is still on the TFP website. I recommend the website over the apps, which are not totally free.

 

 

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1 hour ago, waterbear said:

Since you have not been doing it right I would start with a TA of 60 ppm. If your pH rises too fast and you need to add acid more than once a week to keep it in line then I would try 50 and see. If not, then try 40.

Also once you add the borate (do so AFTER TA is on target) you will find that your pH is more stable as long as you keep the TA in the 40-60 ppm range and DO NOT LOWER THE pH BELOW 7.6 unless you are trying to lower the TA. Borate will possibly raise your TA reading since you are really just titrating the total alkalinity present but it is NOT carbonate alkalinity so it will not cause pH to rise. In fact the boric acid/borate buffer tends to make pH drift downward. You will find that the sweet spot for pH is right around 7.7 and I would not worry about lowering it until it rises ABOVE 7.8 when you should drop it to 7.6 and not lower. Once you have gone through this process you will learn the approx. amount of acid needed to lower your pH each time for your chosen TA and borate levels, which makes things much easier.

Got it thanks!

1 hour ago, waterbear said:

Bleach is normally easy to find but Covid 19 has made it more difficult. Only difference is the concentration, with laundry bleach being 5.25% or 6% and pool chlorine being 10% or 12.5%. FWIW, Pool chlorine is normally referred to as bleach by pool professinals! ;)

Good to know, I also saw your other response :)

1 hour ago, waterbear said:

Common misconception. Shock is a verb. It means raising the sanitizer level high enough to destroy CC or algae and the level needed depends on what you are trying to do AND the current CYA level. For example, in a plaster pool with CYA in the 30-50 ppm range with black algae normally need to be 'nuked' to a FC level of 50 ppm or higher and maintained there for a period of time to kill the black algae. An acrylic spa with a CYA level of 30 ppm needs a shock of 12 ppm to destroy CC. There is no such thing as product named "shock" They will either be a standard chlorine source such as cal hypo, lithium hypo , liquid chlorine, dichlor, or a non chlorine oxidizer such as MPS. Some chloirne sources also include algacides and or clarifiers, which are totally unnecessary in most cases since chlorine is the best algaecide around.

That makes more sense! I'll keep an eye on CC and determine how often I need to shock it, as a verb :) , raising FC to 12ppm. Based on the Taylor FAQ's it looks like 0 is ideal so I know my range (0 to .5)

1 hour ago, waterbear said:

I use PoolMath (search for it on Google). This is the original pool calculator written by JasonLion from TFP and is still on the TFP website. I recommend the website over the apps, which are not totally free.

Found it, that will be very helpful! Thank you again @waterbearfor all of your guidance and insight! This has been a very educational conversation and now it's time to put it into action! I really cannot express how much better I feel just knowing more about how this all works! I'm glad I found this forum! Professionally I am an engineer so working in forums was right up my alley!

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  • 3 weeks later...

@waterbear, thank you again for your time and all of your feedback and advice. Since we last spoke I drained my hot tub, followed @Nitro's full cleanse instruction and then filled it back up and followed all of your instruction and @Nitro's Dichlor/Bleach in a nutshell method. For weeks I've now got perfectly clear and clean water that is amazing. My pH is at 7.6 and my TA is at 60 and everything is staying stable. I added 50ppm of borates and I'm sure that is helping as well. I now have my maintenance process working as it should and know how to measure and adjust as needed...properly. The family and I are loving it, and I couldn't have done it without your education...thank you so much!

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