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Lowering Total Alkalinity

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If you are dealing with a protable spa and have issues with pH and the problem is that is always is low........Just Drain The Spa.

Its just a big bath tub and should be drained 4 times per year.

The real concern is the type of snitzer that you use and how it effects the water chemistry.

If you use Bromine then you wont need to balance the pH. Bromine works better with a pH over 7.8 and will accomadte itself to new tap water just fine.

Chlorine is the bigger issue. If you want to use a atomatic dispenser you are out of luck! Tablet chlorine has a pH of about 2.0 and the pH of the fiberglass of the spa is 7.0. Our bodies and the equipment require a slightly above neutral pH of 7.4. to 7.6 and a bit higher wont hurt either. The problem is, if you use a sanitizer that has a low pH and nothing to buffer it other than the TA of the water then you will need to buffer the pH yourself. Which means EVERY time you as chlorine you need to adjust the pH. And if the Total Alkalinity is allowed to be too high or too low for a period fo time then the pH will tend to drift the same direction. This is why it is easy to use Bromine and when the water does begin to age and a pH drift is noticeable because you need to adjust it weekly then just drain the spa and start over. Water is cheaper than equipment repairs due to corrosive pH.

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If you are dealing with a protable spa and have issues with pH and the problem is that is always is low........Just Drain The Spa.

Its just a big bath tub and should be drained 4 times per year.

The real concern is the type of snitzer that you use and how it effects the water chemistry.

If you use Bromine then you wont need to balance the pH. Bromine works better with a pH over 7.8 and will accomadte itself to new tap water just fine.

Chlorine is the bigger issue. If you want to use a atomatic dispenser you are out of luck! Tablet chlorine has a pH of about 2.0 and the pH of the fiberglass of the spa is 7.0. Our bodies and the equipment require a slightly above neutral pH of 7.4. to 7.6 and a bit higher wont hurt either. The problem is, if you use a sanitizer that has a low pH and nothing to buffer it other than the TA of the water then you will need to buffer the pH yourself. Which means EVERY time you as chlorine you need to adjust the pH. And if the Total Alkalinity is allowed to be too high or too low for a period fo time then the pH will tend to drift the same direction. This is why it is easy to use Bromine and when the water does begin to age and a pH drift is noticeable because you need to adjust it weekly then just drain the spa and start over. Water is cheaper than equipment repairs due to corrosive pH.

A bit of an over simplification. You have to take into account the TA of the fill water. If the pH is always too too then the simple fiix is to bump up the TA a bit so you get more pH rise from outgassing of CO2.

Also, pH is a property of solutions so the ACRYLIC shell of spa would not have a pH. Period! (There are some fiberglass spa shells but the majority are acrylic, btw).Not sure where you get the idea that our bodies and the equipment require a pH of 7.4 to 7.6. The isoelectric point of our skin and hair is actually around a pH of between 3 and 4 and even water at a neutral pH of 7 is "aggressive" to our bodies and causes disruption of the proteins. As far as the equipment the acceptable pH range depends on exactly what we are talking about. Acrylic shells can handle a fairly wide pH range while plaster shells and vinyl liners can suffer some damage from pH that is too low.

Also, how can you say that if you use bromine you don't need to balance the pH? While it is true that bromine is effective over a fairly wide pH range , so is chlorine in the presence of CYA! Also, bromine tablets and MPS (the most common oxidizer used with bromine) are both net acidic and WILL cause both pH and TA to drop over time so they need to be monitored and balanced! Period! That is why a higher TA (carbonation level) is used for bromine and organic chlorine sources than for the inorganic hypochlorites, which are net pH neutral or farily close.This over carbonation will mean that there is more outgassing of CO2, which is the main cause of pH rise in a pool or spa and isnce spas receive a lot of aeration then there is much faster outgassing. It's not a static system, There is interaction between all the water parameters and all the chemicals added and the level of aeration. This is why regular testing with a good test tkit such as a Taylor K2006 for chlorine or K2106 for bromine and regular adjustments of water parameters is needed. You can't just say dump it all and start over. If the fill water has a very high TA then initial fills might require a longer time to balance that weekly maintenance will!

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OK - we just cleaned out the hot tub and refilled. I figure the logical way to "balance" the water would be to adjust alkalinity first, then pH then add chlorine? I assume this because adjusting pH if the alkalinity is off will be difficult and in my dealings, I've always known to adjust pH before adding chlorine - is this correct? The reason I ask is once the tub was full my wife added chlorine before I had a chance to test. I now test (have not tested chlorine yet) and pH is high and alkalinity is VERY high (250 ppm). I figure I will bring the alkalinity down using Muriatic acid and then adjust pH from there.

Have I caused any irreversible damage by adding the chlorine first. Historically my cyanuric acid levels have been high and I remember someone told me the only way to lower this is to start over. Any help?

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You should add chlorine right away so that the water doesn't go south -- bacteria can grow rather quickly doubling in population every 15-60 minutes. Then you can adjust your TA as needed and the pH is adjusted after the TA is set.

The only issue with adding chlorine first is that you need some CYA in the water so you can easily accomplish both by starting out using Dichlor. Do not add bleach (or any other unstabilized chlorine) to the spa with no CYA in the spa (the only exception is with a decontamination procedure).

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You should add chlorine right away so that the water doesn't go south -- bacteria can grow rather quickly doubling in population every 15-60 minutes. Then you can adjust your TA as needed and the pH is adjusted after the TA is set.

The only issue with adding chlorine first is that you need some CYA in the water so you can easily accomplish both by starting out using Dichlor. Do not add bleach (or any other unstabilized chlorine) to the spa with no CYA in the spa (the only exception is with a decontamination procedure).

OK - Thanks. Stabilized dichlor was used (not bleach - will only use bleach once the spa is established and then only after use). For my knowledge, please explain your post "need some CYA in the water". I thought I read where CYA should be at or near 0.

Lastly, then I can infer the process after cleaning/refilling should be chlorinate with a stabilized chlorine, adjust alk., adj. pH then re-test all and then make minor adjustments if necessary?

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So I have a question about keep Br- stable. For the last week I have been checking almost daily and every time do there is virtually no free Br-. So when I see that I add three cap fulls of shock (spa pure oxidizing shock) and get the level up to ~5ppm but after a day or so there is none left. My pH is about 7.6, hardness 280ppm and TA 60ppm tonight when I checked. Any suggestions or great wisdom?

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For my knowledge, please explain your post "need some CYA in the water". I thought I read where CYA should be at or near 0.

Lastly, then I can infer the process after cleaning/refilling should be chlorinate with a stabilized chlorine, adjust alk., adj. pH then re-test all and then make minor adjustments if necessary?

I just meant that you should not start off using bleach after a fresh refill. You don't want to add unstabilized chlorine to the spa water unless you have built up or explicitly added CYA to the water first (an exception to this is if you are doing a decontamination procedure). When you use Dichlor, which is a stabilized chlorine, it adds CYA to the water. After the amount of CYA has built up to around 30 ppm, then you can switch over to using bleach. About once a month you should use Dichlor for a day or two to build up the CYA again since it drops around 5 ppm per month.

Yes, after a refill you chlorinate with Dichlor, but you may not need to adjust the TA right away unless it is high. The reason is that Dichlor is net acidic when accounting for chlorine usage/consumption so using Dichlor cumulatively adding 33 ppm FC to get 30 ppm CYA will have the TA drop by around 12 ppm. If you find that the pH is rising too much even when using Dichlor, then you can lower the TA earlier. If you lower the TA to 50 ppm, then be sure to add 50 ppm Borates, most easily added by using boric acid.

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So I have a question about keep Br- stable. For the last week I have been checking almost daily and every time do there is virtually no free Br-. So when I see that I add three cap fulls of shock (spa pure oxidizing shock) and get the level up to ~5ppm but after a day or so there is none left. My pH is about 7.6, hardness 280ppm and TA 60ppm tonight when I checked. Any suggestions or great wisdom?

Are you referring to SpaPure Spa Oxidizing Shock? That is non-chlorine shock. If you did not initially set up a bromide bank (i.e. add sodium bromide) or have not been using bromine tabs, then there is no bromine being created in your spa. The non-chlorine shock has no bromide to react with to make bromine. The proper way to use bromine is to initially add sodium bromide, usually at a dose of 1/2 ounce per 100 gallons, after which you can use either chlorine or non-chlorine shock to oxidize the bromide to bromine.

It's also possible that you simply aren't adding enough to handle a higher bather load. A bromine level of 5 ppm in 350 gallons would only handle around 20 person-minutes of soaking. You should add more oxidizer if you are soaking more. The general rule is to add whatever amount you need so that you still measure a residual for your next soak and that it never gets to zero (or close to zero) in between soaks.

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So I have a question about keep Br- stable. For the last week I have been checking almost daily and every time do there is virtually no free Br-. So when I see that I add three cap fulls of shock (spa pure oxidizing shock) and get the level up to ~5ppm but after a day or so there is none left. My pH is about 7.6, hardness 280ppm and TA 60ppm tonight when I checked. Any suggestions or great wisdom?

Are you referring to SpaPure Spa Oxidizing Shock? That is non-chlorine shock. If you did not initially set up a bromide bank (i.e. add sodium bromide) or have not been using bromine tabs, then there is no bromine being created in your spa. The non-chlorine shock has no bromide to react with to make bromine. The proper way to use bromine is to initially add sodium bromide, usually at a dose of 1/2 ounce per 100 gallons, after which you can use either chlorine or non-chlorine shock to oxidize the bromide to bromine.

It's also possible that you simply aren't adding enough to handle a higher bather load. A bromine level of 5 ppm in 350 gallons would only handle around 20 person-minutes of soaking. You should add more oxidizer if you are soaking more. The general rule is to add whatever amount you need so that you still measure a residual for your next soak and that it never gets to zero (or close to zero) in between soaks.

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Yes that is the shock that I am using. I realize it's a non-Chloro shock but it is what I have. I plan on switching to bleach when I run out. So as far as a Br- bank, when I filled my spa back in August it was before I came across this forum. Before then I was just going with what the local dealer told me (through in the tablets and you'll be fine) so I did not add in sodium bromide. I have been adding tablets since I changed the water ( about 2 a week) so should have a Br- bank of sorts yes?

So there is 2 of us that use it about twice a week and throw some shock in each time right after. I guess I could need to put more in when I do but at what rate does the ppm of bromine go down on a closed tub that has not been used for several days because like I said ealyer I have been checking almost daily, adding shock after each time I check, and nobody had been in it in days and I still see low Br-.

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Yes, if you have been using bromine tabs for a while, then the bromide bank should be built up.

How long are the two of you soaking? What is the water temperature when you soak? It does sound like you aren't adding enough non-chlorine shock after each soak and now that you are behind it may take an even higher level to catch up. Once you are caught up, then the bromine tabs should be able to provide a background level of bromine to prevent you getting to zero. You should be able to adjust the bromine tab output from the feeder.

Do you have an ozonator? I suspect that you do not.

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The two of us for about 45 minutes on average and the temp of the water is 100F. Ya I have the floater adjusted to more or less a random setting. I haven't gotten a chance to figure out the proper height to set it at. No I do not believe that I have an ozonator. It's a Great Lakes, 5 person, round, 309 gallon spa.

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Two people soaking for 45 minutes in a hot spa would need around 27 ppm bromine to oxidize the bather waste so figure with 100ºF instead of 104ºF perhaps it's around 20 ppm bromine needed. You were only adding enough oxidizer to get to around 5 ppm so that is the cause of your problem (maybe you were more than 5 but it got to 5 when you measured it, but even so you aren't adding nearly enough oxidizer). Add more oxidizer to get the bromine higher. The goal is to add whatever is needed so that you still measure a residual (around 4 ppm bromine) 24 hours later.

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The issue I am having is that my pH always seems to creep down while my alkalinity creeps up. I'm new to hot tubs, so I'm not sure if there is something I am missing??? Any tips, please?

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What kind of disinfectant or other chemicals are you adding to your spa. What are you adding to bring the pH back up? If you are adding "pH Up" which is sodium carbonate (usually -- sometimes it's sodium bicarbonate), then that will increase both pH ad TA so could be why your TA is rising. What is your current TA level? Perhaps you need to target a higher TA level if you are using an acidic source of disinfectant.

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i am using pH Up to bring up the level, and granulated chlorine for disinfectant. my latest levels were pH 7.2 and TA 185. over the next couple days without adding any chemicals, the pH will drop to 6.8 or so, and the TA usually remains somewhat constant.

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Well, the TA creeping up is explained because you are using pH Up and that increases both pH and TA, but increases TA more than it drops from any net acid (such as from the type of chlorine you are using).

What are the ingredients in the granulated chlorine? Is it nearly 100% Dichlor (dichloro-s-triazine or sodium dichloroisocyanurate)? Though that is net acidic, you usually don't see the pH drop that much especially when the TA is higher. You may not have much aeration of the water -- are you running any aeration jets such as when you are using the spa?

So if there were little or no aeration of the spa, then the chlorine you are adding and then getting used/consumed results in the pH and TA dropping, but then the pH Up you add increases the pH back to where it was but increases the TA to be higher than what it was. I'm just surprised that with the high TA that the pH isn't being more stable.

Are you adding any other chemical such as non-chlorine shock (MPS)? That is even more acidic than the chlorine.

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The only other product I use is "Waters Choice Chemical Free Enzymes", in the small blue bottle, 1 cap full every 2 weeks. My chlorine is Natural Chemistry's Spa Chlorine Concentrate, it is Sodium Dichloro-s-Triazinetrione....100%, Available Chlorine Content....62%. The hot tub is used virtually daily, but rarely does iit run with the aeration jets on. So, if I run the aeration jets every time we are in, then that should help raise the pH?If so, then I could use the pH Down to lower both the pH as well as the TA?

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Yes, if you run the aeration jets when you are in, then the pH likely won't drop as much and might even rise instead. If it rises, then you'd add pH Down (sodium bisulfate aka dry acid) that will lower both the pH and the TA. The TA may get lowered to a sweet spot where the pH is stable, but the use of Dichlor will continue to slowly lower the TA level. The following chart shows the effects of the different chemicals you are or can be using:

Chemical ....... pH . TA
Dichlor ............. - ... - ... (net effect including chlorine usage/consumption)
Bleach ............. 0 ... 0 ... (net effect including chlorine usage/consumption)
pH Up .............. + . ++ ... (assumes sodium carbonate is used)
Borax ............... + ... +
pH Down .......... - ... -
Alk. Up ............. 0 ... + ... (pH will rise some if it is low, but not much if it is already higher)
Aeration ........... + ... 0

So if you have enough aeration at a given TA level to have the pH be stable when using Dichlor, then if you need to raise the TA you can use baking soda (sodium bicarbonate). Arm & Hammer Baking Soda will be less expensive than Alkalinity Up from the spa store and it's the identical chemical. In fact, Arm & Hammer Super Washing Soda (careful: NOT the laundry detergent) is identical to pH Up (when it's sodium carbonate). To raise the pH with less of an effect on TA, you can use 20 Mule Team Borax.

Keep in mind that if you continue to use Dichlor-only, then your Cyanuric Acid (CYA) will build up making the chlorine less effective. That usually means you'll need to change the water sooner as it will often get dull/cloudy. For your daily use, the Dichlor-then-bleach method may work better for you. It is described in this sticky, but after switching to bleach you may find the pH rises too much (you may want to go back to not having any aeration) and so your TA target may need to be lower at around 50 ppm and the use of 50 ppm Borates (usually from boric acid) is helpful in lowering the rate of pH rise. Note that the use of bleach is roughly pH neutral because though bleach raises the pH upon addition, the usage/consumption of chlorine is acidic. That's why Dichlor is net acidic because it is fairly pH neutral upon addition but the usage/consumption of chlorine is acidic.

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thanks for the info!!! really appreciate it. have had the aeration jets running on and off for a few hours yesterday and will again over the next few days. i will let you know how it goes!

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For my knowledge, please explain your post "need some CYA in the water". I thought I read where CYA should be at or near 0.

Lastly, then I can infer the process after cleaning/refilling should be chlorinate with a stabilized chlorine, adjust alk., adj. pH then re-test all and then make minor adjustments if necessary?

I just meant that you should not start off using bleach after a fresh refill. You don't want to add unstabilized chlorine to the spa water unless you have built up or explicitly added CYA to the water first (an exception to this is if you are doing a decontamination procedure). When you use Dichlor, which is a stabilized chlorine, it adds CYA to the water. After the amount of CYA has built up to around 30 ppm, then you can switch over to using bleach. About once a month you should use Dichlor for a day or two to build up the CYA again since it drops around 5 ppm per month.

Yes, after a refill you chlorinate with Dichlor, but you may not need to adjust the TA right away unless it is high. The reason is that Dichlor is net acidic when accounting for chlorine usage/consumption so using Dichlor cumulatively adding 33 ppm FC to get 30 ppm CYA will have the TA drop by around 12 ppm. If you find that the pH is rising too much even when using Dichlor, then you can lower the TA earlier. If you lower the TA to 50 ppm, then be sure to add 50 ppm Borates, most easily added by using boric acid.

 

CYA has risen to 40. I have stopped using the dichlor to keep CYA from getting higher and since I have a pool as well I am using Vertex concentrate (Pool Shock) as the sanitizer (basically diluted sodium hypochlorite). pH is ALWAYS high. I lowered alk. to 70 and still each time I use muriatic acid to lower pH the next time I check it is high.

Just checked and pH was high, Alk is at 80, chlorine is good very little combined chlorine (negligible). CYA 40 and calcium hardness is good as well. I fell like I am always adding muriatic acid and pH is always high. The spa is not used between tests - it's been hot here so we haven't used the hot tub for months and pH keeps creeping up. I continually add muriatic acid until my TA gets low.

Why can I not control the pH week to week.

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Spas are hotter water and have more aeration so they outgas carbon dioxide and that has the pH rise. We normally recommend to do the following for spas using hypochlorite sources of chlorine such as bleach or chlorinating liquid. First is to lower the TA level to 50 ppm. Second is to add 50 ppm Borates (usually from boric acid such as from Duda Diesel or The Chemistry Store. Third is to not add acid unless the pH gets above 7.8 and do not lower the pH below 7.5 (in normal use -- when lowering the TA you lower the pH a lot to accelerate the process).

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Just received my new spa today and trying to follow the Nitro method. First step is getting TA & PH in balance.

I started with the following water from the tap:

PH - 8.0
ALK - 170
CH - 210
I have been adding dry acid (sodium bisulfate) as instructed. A bit at a time, aerate, and then more.
The TA was dropping but couldn't get the PH to stay below 8.0 after aeration.
I'm finally at the point where PH is stable (for the past 60 minutes) but my TA is now at 30.
Help!!! Is my TA too low and could I be causing damage?
What do I do to get my TA in the 50 - 80 range without my PH rising?

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On 9/6/2016 at 4:46 PM, vanduse1 said:

Just received my new spa today and trying to follow the Nitro method. First step is getting TA & PH in balance.

I started with the following water from the tap:

PH - 8.0
ALK - 170
CH - 210
 
 
I have been adding dry acid (sodium bisulfate) as instructed. A bit at a time, aerate, and then more.
 
The TA was dropping but couldn't get the PH to stay below 8.0 after aeration.
 
I'm finally at the point where PH is stable (for the past 60 minutes) but my TA is now at 30.
 
Help!!! Is my TA too low and could I be causing damage?
 
What do I do to get my TA in the 50 - 80 range without my PH rising?

I think I'm all set now... I raised the TA up a bit ~50 now. The PH was still 8+ but when I let it sit overnight it settled back down about 7.6!!!

 

Looking forward to getting started on this new method.

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I don't know what I'm doing wrong but I cannot drop my TA.  My TA is 180+ and every attempt at lowering it drops my PH way low.  Ive maybe seen around 125-130 at the lowest but my PH is then super low in the mid 6's.  When I raise my PH to 7.4ish my TA is again off the charts.  I'm using Spa up and Spa down but both seem to either drop or raise both TA and PH even after the aerating my ph is dropping with the TA.  My local spa dealer can't figure it out, they've done 4 empties and refills in the 6 months I've owned the tub.  I was using a Bromine system but switched to Chlorine Spa 56 for my sanitizer.  Any suggestions?

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