Adding pH down increased pH in hot tub

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M

mxnathantamar

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Jul 19, 2018
46
The Villages/FL
I am doing the initial chemical balancing on my new hot tub. I filled the tub and tested the untreated water:

TA = 130
pH = 7.8

I added 2 oz. Chlorox pH Down, hoping to bring down both the TA and the pH, ran the filter and jets for 30 minutes, then retested:

TA = 100
pH = 8.0 or more

I then checked the CH = 120, just in case it had anything to do with the pH increase.

Do I add more pH Down? I have not added any chlorine or CYA products, yet.
 
Running the jets in a hot tub with high TA raises the pH extremely fast. It's a lot of aeration. Adding the dry acid did not raise your pH.

If you continue to dose your pH down to 7.2 and retest as often as every half hour you should be able to get your TA down around 60 and better stabilize your pH fairly quickly.
 
No, running the jets to mix is good. You just need to make the water less susceptible to CO2 outgassing, which is what drives the pH up while the jets are running. That's what lowering the TA will do.
 
The water where I live has fairly high CH and TA too. Before I discovered TFP I was always chasing my pH around up and down everytime I did the chemicals. This last time, I did the startup as per the sticky posts on this forum's instructions, repeatedly knocking the pH down to 7, aerating until pH back at 7.6 or higher, knocking pH to 7 again, etc., until I got TA to 60. After doing that my pH pretty much stayed rock steady where I wanted it at 7.5 - 7.6 and I never hardly had to any adjusting anymore. Do the same with starting up your tub and you'll be golden.
 
DangerBoy said:
The water where I live has fairly high CH and TA too. Before I discovered TFP I was always chasing my pH around up and down everytime I did the chemicals. This last time, I did the startup as per the sticky posts on this forum's instructions, repeatedly knocking the pH down to 7, aerating until pH back at 7.6 or higher, knocking pH to 7 again, etc., until I got TA to 60. After doing that my pH pretty much stayed rock steady where I wanted it at 7.5 - 7.6 and I never hardly had to any adjusting anymore. Do the same with starting up your tub and you'll be golden.
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Thanks.
Donldson said:
No, running the jets to mix is good. You just need to make the water less susceptible to CO2 outgassing, which is what drives the pH up while the jets are running. That's what lowering the TA will do.
Click to expand...
Thanks.
 
For the past 3 days I have been trying to balance the pH and TA on my new hot tub. I just performed my 23rd test. My untreated water had a pH of 7.8 and a TA of 120-130. I have had, during these 3 days, since I started treating the water, TAs ranging from 0 to 100, and pHs ranging from yellow to over 8.0. The only chemicals I have added have been pH down and alkalinity increaser, each added separately, each time using filtration plus 30 minutes of running the jets. I have gotten the TA to 60 twice, but with a pH of 7.8-8.0. Needless to say, I'm exhausted. I am going away in 3 days for an 8-day trip, and at this rate, I may not even have it balanced by then, let alone get to try out the tub. I did add a few inches of fresh water today, simply to make up for all that I have taken out by repeated testing, but that didn't seem to change the chemistry much. I am wondering if I need to add muriatic acid or borates. I intend to use the hot tub as a pool, at temperatures like those of a heated pool, and plan to allow my small dog in the tub. He doesn't seem to drink pool water, but, of course, a small amount could still be ingested. (As far as borates affecting a dog's fertility, he is neutered.) In previous months, I had 2 small AG pools that I kept somewhat balanced, without too much difficulty, but I allowed more leeway in pH (often 7.8-8.0), and had TAs of 100-130.

TA= 80
pH= >8.0

The hot tub guide recommends a pH of 7.2-7.8 and TA of 60-120. I have been trying to get a pH of no more than 7.6 and a TA of 60, based on replies on this forum to my previous posts and on what I have been reading online. My second last test showed a pH of 7.8 and TA of 80, which would be in line with the guidelines of the manual. I am wondering whether that is the best I can get.
 
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mxnathantamar said:
The only chemicals I have added have been pH down and alkalinity increaser, each added separately,

TA= 80
pH= >8.0
Click to expand...

The pH down and alk+ are working against each other........even though you are adding them separately.

My suggestion is stop trying to manipulate TA and just manage pH. When pH climbs above 8, take it down to 7.4ish. Eventually, pH will begin to stabilize because your TA is also dropping and you will need to adjust less frequently. Do it in increments, so you don’t overshoot. Do not add borates a until it does stabilize.

My spa and water likes for TA to be 50-60....pH stays rock solid (7.4-7.6)at that TA. Then I add boric acid. Your water might stabilize a little higher or lower.
 
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My suggestion is to stop fussing with it and just get in and enjoy your new hot tub. There is no reason you can't use the tub based on what you have said so far. Make sure there is sufficient chlorine in the water and get in there!!

Also, why would you add alkalinity increaser? That is the opposite of what you were trying to do. Honestly, you are trying too hard for perfection. Perfection isn't obtainable and pH will vary. Add muriatic acid when pH gets to 8 or above and dose to bring pH down to 7.4-7.6. TA will drop when you add the acid. Eventually you will find a happy medium.
 
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Teald024 said:
My suggestion is to stop fussing with it and just get in and enjoy your new hot tub. There is no reason you can't use the tub based on what you have said so far. Make sure there is sufficient chlorine in the water and get in there!!

Also, why would you add alkalinity increaser? That is the opposite of what you were trying to do. Honestly, you are trying too hard for perfection. Perfection isn't obtainable and pH will vary. Add muriatic acid when pH gets to 8 or above and dose to bring pH down to 7.4-7.6. TA will drop when you add the acid. Eventually you will find a happy medium.
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Thanks a lot, Teald024. I didn't add any alkalinity increaser at first, only pH Down. But, in my repeated attempts to lower the pH, the TA went down to 0 - 50 on various tests; only then did I add alkalinity increaser, which caused the pH to rise again. I have never used muriatic acid before, but was planning to buy some today and try that. However, I tested the water once more last night, after it had just sat for 6 - 7 hours while running filtration but no jets, and the TA had gone down from 80 to 70, seemingly on its own, with a pH of 8.0. So I added just a tiny amount of pH Down, ran the filtration all night, but again, no jets. This morning the TA was 60 and the pH was 7.2, at last, very good!! I just now added dichlor. I still may need to add calcium hardness increaser, but I had run out of it, so have to go buy some.

Also, a question, if I should run out of any of the Taylor test chemicals and do not want to wait for them to arrive in the mail, are these available individually at the pool stores? And, if they do not have the Taylor brand, could other brands substitute until I receive the Taylor testers?

TA = 60
pH = 7.2
 

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Tpopz said:
The pH down and alk+ are working against each other........even though you are adding them separately.

My suggestion is stop trying to manipulate TA and just manage pH. When pH climbs above 8, take it down to 7.4ish. Eventually, pH will begin to stabilize because your TA is also dropping and you will need to adjust less frequently. Do it in increments, so you don’t overshoot. Do not add borates a until it does stabilize.

My spa and water likes for TA to be 50-60....pH stays rock solid (7.4-7.6)at that TA. Then I add boric acid. Your water might stabilize a little higher or lower.
Click to expand...
Tpopz said:
The pH down and alk+ are working against each other........even though you are adding them separately.

My suggestion is stop trying to manipulate TA and just manage pH. When pH climbs above 8, take it down to 7.4ish. Eventually, pH will begin to stabilize because your TA is also dropping and you will need to adjust less frequently. Do it in increments, so you don’t overshoot. Do not add borates a until it does stabilize.

My spa and water likes for TA to be 50-60....pH stays rock solid (7.4-7.6)at that TA. Then I add boric acid. Your water might stabilize a little higher or lower.
Click to expand...

Thanks, tpopz. See my post to Teald024. This morning my TA and pH were finally very good. I am beginning to think that either running the jets, or testing too soon after running them, might be giving me different numbers than I would get if I wait a little while before testing; this is just a guess, since I am totally new to hot tubs and never used any aeration on my pools.

TA = 60
pH = 7.2
 
mxnathantamar said:
I still may need to add calcium hardness increaser, but I had run out of it, so have to go buy some.
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What is your CH level? If your CH is above 60ppm, then there is no need to add more calcium. Don't buy any right now.


mxnathantamar said:
If I should run out of any of the Taylor test chemicals and do not want to wait for them to arrive in the mail, are these available individually at the pool stores? And, if they do not have the Taylor brand, could other brands substitute until I receive the Taylor testers?
Click to expand...
It is not likely that pool stores will carry the reagents you need. Also, if a PS does have the reagents, I'd be concerned on how long they sat on the shelf. The only critical reagents are the ones for pH and FC/CC. You will have enough advanced warning that you are about to run out of reagents to give you time to order more. I highly recommend getting the reagents from TFTestkits.net. They are very competitive in price, ship quickly, and will always be fresh.
 
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Just did a clean/drain/fill on my hot tub yesterday.......pool is starting to get uncomfortably cool.

Anyway, I was adjusting pH/TA yesterday too. It usually takes me 3 small adjustments to hit my targets. I usually circulate the first acid addition for 30min then aerate for 45min then test. As I approach my TA target, I aerate more before testing......or test a couple times to see if pH has topped out.

Enjoy the hot tub! As much as I love my pool, cool weather and a hot tub soak is awesome.
 
Teald024 said:
What is your CH level? If your CH is above 60ppm, then there is no need to add more calcium. Don't buy any right now.



It is not likely that pool stores will carry the reagents you need. Also, if a PS does have the reagents, I'd be concerned on how long they sat on the shelf. The only critical reagents are the ones for pH and FC/CC. You will have enough advanced warning that you are about to run out of reagents to give you time to order more. I highly recommend getting the reagents from TFTestkits.net. They are very competitive in price, ship quickly, and will always be fresh.
Click to expand...
OK, thanks, Teald024. Everything checked out well enough today “for now,” and I got into the tub. And that is the culmination of at least 2 years of research and experimentation since I first got the idea of putting a little AG pool in my screen porch. I could not afford an inground pool. I have access to many pools in my retirement community, but I have always wanted to have my own little bit of water. I had a kiddie pool and a therapy pool set up this year until recently, but the water was too cold, even in the summer here in Florida. I would get in one inch at a time and never could get in all the way; the cold was a shock. I planned to get a heat pump and an electrical upgrade, but couldn’t afford those, either; the plug-and-play hot tub was much more affordable. So, today was the first time I could immediately get completely into any of my “pools” (at 88 degrees, so far), and it was great. My CH was 150, so I did nothing. I already bought the product, just in case I needed it, but I might be able to return it; if I don’t need something right now, I can certainly use the money. The pH and chlorine (from Dichlor) were high and the CYA was low, but I went in, anyway, and had no problems. I will keep working on my numbers. I have gotten Taylor testers from Amazon, but will check into getting them directly from Taylor.

TA=60
CH=100
pH=7.8-8.0
FC=5.8
CC=0
CYA does not register, as yet, in the Taylor test.
 
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