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Nitro's Approach To Water Maintaince


Nitro

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Well, I have re-checked again (twice) very carefully.

FC 5

TA 75

pH 7.8

CH 175

What do you think? Should I do anything?

If it were me I'd keep tweeking it until I got it perfect, but I like tweeking water. However, if I were you I would leave it alone for now. Keep an eye on pH, test after you use the tub. If it drifts above 8.0 you can add a little acid to bring TA down. Only add 1 TBS at a time, then aerate for 30 min, then check TA/pH again. If pH is 7.6-7.8 leave it until next time. If you manage to get your TA down around 60, should be well tuned.

However, and this is most important, the reason we try to get our TA tuned is so we don't have to mess with it as often. If we are messing with it more trying to get TA tuned, that kinda defeates the purpose. :)

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However, and this is most important, the reason we try to get our TA tuned is so we don't have to mess with it as often. If we are messing with it more trying to get TA tuned, that kinda defeates the purpose. :)

Amen to that! As waterbear has often said "a pool (or spa) is NOT a science experiment!".

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However, and this is most important, the reason we try to get our TA tuned is so we don't have to mess with it as often. If we are messing with it more trying to get TA tuned, that kinda defeates the purpose. :)

Amen to that! As waterbear has often said "a pool (or spa) is NOT a science experiment!".

I seem to enjoy 'tweeking' water too, however I seem to make mistakes!! So... I will do as you both say, and leave it alone for a bit. I will test the TA and pH as directed. Tonight I will only add the Purox after a soak.

Also, if you guys don't mind, I will re-test again tomorrow and post the results.

And yes, the stain did come out. It looks great. Hopefully, it won't come back.

I WILL get good at this!!!

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However, and this is most important, the reason we try to get our TA tuned is so we don't have to mess with it as often. If we are messing with it more trying to get TA tuned, that kinda defeates the purpose. :)

Amen to that! As waterbear has often said "a pool (or spa) is NOT a science experiment!".

I seem to enjoy 'tweeking' water too, however I seem to make mistakes!! So... I will do as you both say, and leave it alone for a bit. I will test the TA and pH as directed. Tonight I will only add the Purox after a soak.

Also, if you guys don't mind, I will re-test again tomorrow and post the results.

And yes, the stain did come out. It looks great. Hopefully, it won't come back.

I WILL get good at this!!!

ok, one more thing tonight---- just to be perfectly clear and not to make a mistake- when you say 'add a little acid to bring TA down" , what exactly do I use again, and are you sure I should use a tablespoon?

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ok, one more thing tonight---- just to be perfectly clear and not to make a mistake- when you say 'add a little acid to bring TA down" , what exactly do I use again, and are you sure I should use a tablespoon?

Theoretically, adding one Tablespoon (Volume) of Dry Acid to your 380 gal tub should lower your TA by ~5 ppm. Richard can correct me if I'm wrong here. I say Theoretically, because your numbers are not very predictable.

The main thing to remember is, be consistent. Just add 1 TBS, aerate and check the next day etc. That way your TA SHOULD move slowly down (i.e. 75, 70, 65, 60). BUT don't add acid unless your pH is above 8.0.

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Theoretically, adding one Tablespoon (Volume) of Dry Acid to your 380 gal tub should lower your TA by ~5 ppm. Richard can correct me if I'm wrong here. I say Theoretically, because your numbers are not very predictable.

The main thing to remember is, be consistent. Just add 1 TBS, aerate and check the next day etc. That way your TA SHOULD move slowly down (i.e. 75, 70, 65, 60). BUT don't add acid unless your pH is above 8.0.

Yup. That's correct. If you limit the dry acid to one tablespoon, that shouldn't go to far at lowering the pH and will lower the TA by about 6 ppm each time this is done. If there were no Borates, the pH would get lowered from 8.0 to 7.4 at a TA of 80. With Borates, it will move a lot less. It will be interesting to see what it does -- perhaps the Omni product Laura used wasn't as strong a Borates product as we thought -- we'll see.

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Theoretically, adding one Tablespoon (Volume) of Dry Acid to your 380 gal tub should lower your TA by ~5 ppm. Richard can correct me if I'm wrong here. I say Theoretically, because your numbers are not very predictable.

The main thing to remember is, be consistent. Just add 1 TBS, aerate and check the next day etc. That way your TA SHOULD move slowly down (i.e. 75, 70, 65, 60). BUT don't add acid unless your pH is above 8.0.

Yup. That's correct. If you limit the dry acid to one tablespoon, that shouldn't go to far at lowering the pH and will lower the TA by about 6 ppm each time this is done. If there were no Borates, the pH would get lowered from 8.0 to 7.4 at a TA of 80. With Borates, it will move a lot less. It will be interesting to see what it does -- perhaps the Omni product Laura used wasn't as strong a Borates product as we thought -- we'll see.

So, we were in the tub for about 45 min. areated for about 20 or so..... (hard to keep exact track sometimes)

when I got out the pH was still 7.8 and the TA was still 75. The FC was down to almost 0 (just used a test strip). I added 6 oz. purox. When I tested at 4ish, the FC was 5, so I can see that your figures about the usage of the purox are right, and I will remember!

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So, we were in the tub for about 45 min. areated for about 20 or so..... (hard to keep exact track sometimes)

when I got out the pH was still 7.8 and the TA was still 75. The FC was down to almost 0 (just used a test strip). I added 6 oz. purox. When I tested at 4ish, the FC was 5, so I can see that your figures about the usage of the purox are right, and I will remember!

Great! Then you can leave TA alone, for now. BTW, a TA of 75 isn't terribly high, so you might not have to add acid for a week. Just keep an eye on pH, and of course FC.

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  • 2 weeks later...

Anti-Spam Bumpitization! For new peeps, this is what you need. Press print, cut/paste, whatever works. This is the info your pool chemical supply would be happier if you didn't know. You really can cut your spa maintainence chemical costs in half, and cut the time spent guessing why your water is smelly/cloudy by 100%, and increase the time you proudly share your crystal clear sanitary hottub with friends and family by 100%.

DO NOT be daunted by what may first appear to be a chemistry lesson ...not so much. Remember, knowing how to sanitize a spa is very sexy! ...you know, as opposed to what can happen when you don't know. SO READ and stop weeping, and give the Old Gang Crew at poolspaforum some props. Shouts out to all moderators and "chem geek" [Richard] and "water bear" and the author of this post "Nitro" who have helped so many "get their soak on"!

Bo

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  • 2 weeks later...
  • 1 month later...

Hello spa gurus. New guy, first post, just drained my brand new 2-month old dichlor-dosed Jacuzzi due to a sky-high stabilizer reading. (300+ ppm) :huh:

I'm going to switch to the dichlor/bleach method if someone can just reassure me about the bleach business. Why are

there so many dire warnings out there about not using bleach in hot tubs? I already get the part about pure bleach with no CYA buffer being a problem. Is that really the main reason the warnings are out there?

OK, for the new fill (well water)....I've raised the CH to 250 , the TA is starting about 100, and the pH is well below 7. Already hit the tub with 1 TBS dichlor. If I add ph up, the TA will go up too right? So will aeration alone fix my low ph?

Oh yeah, what's Purox?

Thanks and I sure am glad to find some smart people here. The guys in the pool supply stores are giving me migraines. Bless their hearts.

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The warnings about bleach are not only about using it exclusively with no CYA in the water which would make it too strong, but also that using any hypochlorite source of chlorine (bleach, chlorinating liquid, Cal-Hypo, lithium hypochlorite) will tend to make the pH rise due to aeration and high pH can lead to scaling. So you need to manage this by having a lower TA level. For some spas, such as those with ozonators that aerate a lot, there may not be a good solution as the pH rise may be too much unless one is willing to frequently add acid.

You've already raised the CH too much. The higher temperature of spa water makes the water more likely to scale so you need less CH. In a spa, you usually do not want the CH to be above 150 ppm (if you have a very low TA such as 60 ppm and your CYA is 20-40 ppm, then a higher CH of 200-250 ppm is OK).

Yes, if you aerate the water, the pH will rise with no change in TA. So do NOT add any pH Up as that will raise both pH and TA and will increase the carbonates in your water -- you've already got plenty and may need to lower the TA after your pH is higher by adding more acid and doing more aeration. Just so how things go after Dichlor then bleach. If after using bleach you find the pH rises too much, lower the TA level.

Purox is a brand of chlorinating liquid -- essentially more concentrated bleach.

Richard

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The warnings about bleach are not only about using it exclusively with no CYA in the water which would make it too strong, but also that using any hypochlorite source of chlorine (bleach, chlorinating liquid, Cal-Hypo, lithium hypochlorite) will tend to make the pH rise due to aeration and high pH can lead to scaling. So you need to manage this by having a lower TA level. For some spas, such as those with ozonators that aerate a lot, there may not be a good solution as the pH rise may be too much unless one is willing to frequently add acid.

Can a weekly MPS shock help reign in the ph rise from the bleach?

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Can a weekly MPS shock help reign in the ph rise from the bleach?

Any source of acidity can do that. Yes, using MPS is somewhat acidic. Using Dichlor is more acidic, but builds up CYA. And of course you can just add some acid (e.g. dry acid -- sodium bisulfate). You can minimize the rate of pH rise by having a lower TA, having a somewhat higher pH target (don't try and get below 7.5) and minimizing aeration (turn off unused jets).

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i just want to thank everybody again for contributing to this site. I have been reading for hours and have learned A LOT. i am also now convinced that my local spa dealer has NO CLUE what it really takes to keep a hot tub safe (his advice, add perfect pH, then one cap full of chlorine per week,and one cap full of shock per week; THAT'S IT!). anyway, i do have a few questions as i start my journey toward the dichlor/bleach method.

1. i plan to use a borax/acid combination. at what step in the above procedure would rec'd doing this. I am going to mix the borax and acid in a large bucket of water and make sure it is pH neutral before I add it; but plan to add it all at once. Does this plan sound OK? I had also planned to do this prior to adding dichlor.

2. after many hours of reading, both from the people who love the bleach method and from the people it has failed, i am wondering if borax is the key. the two things i have noticed about the failures is that they tend to have a ozone device and they aren't using borax. just wonder if i am on to something. . .

3. will CYA leave if the chlorine drops to zero? at times, and unavoidably, we travel for a few days to a week at a time. i know we should use bromine but my wife is allergic. i want to find somebody to add chlorine (and check on the cats) daily, but if i don't and return to find a hot tub without chlorine, should i shock and start again with dichlor or continue with bleach?

thanks again, i really appreciate it.

Port

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Port,

As for when to add the Borates, anytime is fine so after a refill of the tub is fine. It will help maintain the pH when you initially superchlorinate with Dichlor. There are pH neutral forms for adding Borates -- basically products that have mostly boric acid. Proteam Supreme Plus (as shown here) is one such product. If you make a mixture on your own using 20 Mule Team Borax and acid (Muriatic Acid or dry acid), then you can certainly do this in a bucket as you've indicated so that you know it's roughly pH neutral. Just remember that a bucket will take tiny amounts of chemical to adjust the pH if it's already "close". Just get it in the ballpark between 7.0 and 8.0. It won't change the bulk spa water pH by very much. I worry that you'll be spending your time swinging from too high to too low pH back and forth.

As for the spa after Borates are added, certainly the Borates will help stabilize the pH, but it won't change the amount of acid that would need to be added if you had an ozonator. It just slows down the pH rise, but it also takes more acid to move the pH down when it does rise. So I'm sure it would still be annoying since I think one of the objections wasn't just the frequency of acid addition, but having to add it at all and in quantity. The only known solution to lowering the cumulative acid quantity is to have a lower TA (and less aeration or a higher pH target with lower CH to prevent scaling).

The CYA will not leave unless you dilute the water. The FC going to zero doesn't change the CYA level. You will need to shock the water when you return in order to ensure there's nothing in it. Obviously, it would be better to have someone add some chlorine and with no one using the tub the FC may drop more slowly though would still need some added after some number of days. Over an extended period of time (months), some people notice the CYA dropping, possibly from oxidation by the chlorine. If that happens, just use Dichlor for a brief time to build it back up. You could probably check your CYA level after a couple of months just to make sure there's enough.

Richard

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As for the spa after Borates are added, certainly the Borates will help stabilize the pH, but it won't change the amount of acid that would need to be added if you had an ozonator. It just slows down the pH rise, but it also takes more acid to move the pH down when it does rise. So I'm sure it would still be annoying since I think one of the objections wasn't just the frequency of acid addition, but having to add it at all and in quantity. The only known solution to lowering the cumulative acid quantity is to have a lower TA (and less aeration or a higher pH target with lower CH to prevent scaling).

Someone posted that aeration only occurs when the waterfall/jets/bubblers are running AND the tub cover is removed. If this is truly the case, then why does the ozonator generally cause the pH to rise 24/7?

Or did I misunderstand the relationship between raising pH with air and the placement of the hot tub cover?

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Someone posted that aeration only occurs when the waterfall/jets/bubblers are running AND the tub cover is removed. If this is truly the case, then why does the ozonator generally cause the pH to rise 24/7?

Or did I misunderstand the relationship between raising pH with air and the placement of the hot tub cover?

You didn't misunderstand. There is no question that a cover can limit the amount of outgassing. In my own pool, I have a opaque electric safety cover and it significantly stabilizes the pH in my pool, but when the pool was used every day instead of 2-3 times per week, I noticed an increase in the rate of pH rise. In my case, it was probably due to the extra time it was open since the rate of rise approximately doubled.

There is some buildup of gas under the cover until equilibrium is reached, but it's not enough to show up a pH rise if the air were not circulated away from the water. On the other hand, if an ozonator is pulling in air from outside the hot tub and injecting it into the water, then there is a small constant stream of air being pushed out from under the hot tub cover. This might be enough over time to remove some of the excess carbon dioxide from under the cover, but it does seem surprising that this could have enough of an effect. I suppose that if the volume of air above the water is fairly small, then it wouldn't take a lot of ozonator air to turn it over quickly. This is just speculation.

Richard

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I have an update for this thread.

I refilled my tub approx 2 months ago. I have been using it with 2 people (me and the misses) approx 2-4 (3 average) hours per week. I had one party, 4 people for 4 hours. My Chlorine Demand (CD) went up after the party to 50% per day, steady for a few days. After shocking (12 ppm FC) for a couple days, and a week of keeping the FC around 6 ppm, I finally got the CD back down to ~30%. My FC has never dropped below 1 ppm at any time. My Combined Chlorine (CC) rose to 0.5 ppm after the party, and hasn't moved since (before the party it was zero).

I have been adding 2-3 oz of bleach every 3-4 days to maintain the FC above 1 ppm with no one using the tub. After me and the misses use the tub for a couple hours, I add ~4 oz bleach (to bring FC to ~6 ppm). The next day I add another 4 oz (6 ppm FC), and the CD is back to normal (~30%).

My pH has been rock solid at 7.8 since the refill 2 months ago, and I have not added any type of Acid since the inital dose. My TA is 60 ppm, my CH is 200 ppm, my CYA is 30 ppm and my Borates is 50 ppm. At this rate my water should last me for the next decade (just kidding). Actually, I plan on it lasting well into the spring, unless I start having more parties. :)

Bottom Line:

1) pH rise is a non-issue. I assume Borates is the key here. Also, I don't have an Ozonator.

2) Without anyone using the tub, you can expect to go 3-4 days with FC starting at 5-6 ppm, and up to 7 days after a shock (10-12 ppm) before your FC drops below 1 ppm. So, that means it's not neccassary to add chlorine everyday (or even every other day), unless you're using the tub often. The key is to keep your Chlorine Demand (CD) low (~30). If your CD is high (>50%), expect to add chlorine every couple days

3) If you have hot tub parties (or use your tub a lot), expect your CD to go up (>50%). The only thing that will bring it down is High Chlorine, Time or a Water Change. I maintained my FC at 12-6 ppm for two days, and then 6-3 ppm for almost a week before I got my CD back down to ~30%. I suppose if I maintained it between 12-6 ppm consistantly it would have only taken 3-4 days. However, I didn't want to subject my tub/cover to that high of FC for that long.

EDIT: I forgot to mention MPS. I haven't used any on this fill. However, MPS should lower CD also.

I hope that helps you to better understand this method. IMHO, this method is VERY easy to learn and use.

Happy Tubbing :)

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  • 1 month later...

I updated the first post in this thread. I added some info about Chlorine Demand. I'm finding it to be a great indicator of the health of my water. My current CD is 25%.

My water is now around 4 months old, and I have no signs of problems. It looks, smells and feels as good as the day I filled it. The water is not showing any signs of sluggishness. Bubbles disappear in just a few seconds, after turning the jets off.

I did add a little Acid (1oz) to lower my TA from 60 to 55ppm a few weeks ago, because my pH crept up to 8.0. Other than that, I've just added bleach about every 3 days, and after soaks.

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  • 1 month later...

I just purchased some bleach from the store today. It is No-Name brand here in Canada from The Superstore. It is 6% Sodium Hypochlorite Ultra Unscented Bleach.......the question I have is that it has a bit of a yellow color to it. Is this okay to use??

Also, my CYA measured at 100ppm today.....I know, too much Diclor........how can I lower it other than a partial drain?

Thanks,

Steve aka SAFASTRO

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Steve,

Bleach and chlorinating liquid have a yellow-to-green color to the liquid. That is normal.

As for lowering CYA, dilution is pretty much the only way.

Richard

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