What is a good source of water chemistry information?

[BB_Mike]

I just bought a used 2015 Master Spa Twilight series and need to decide on my approach to water maintenance.  It has ozone.  My last tub (10 years ago) used chlorine and it had a  chlorine smell and left skin feeling dry and itchy.  So I was thinking Bromine for this tub.  As I researched, my head started to exploded, then I discovered mineral sticks and my head did explode.  Can you provide some links to internet pages with hot tub water approaches that does not have a sales influence or very old information?  I figure some of this new technology like a copper + zinc ionizer or a mineral stick sitting inside my filter might be a good investment.

 

Here is one example:  https://www.swimuniversity.com/hot-tub-mineral-sanitizer/
Seems legit and is what I am leaning towards following.

I am learning a lot on this forums, but I am having to paste together various inputs to draw a conclusion from.

 

Thanks.

[RDspaguy]

The best source of info that I know of is @waterbear.

[BB_Mike]

Yes, his posts are a good read for sure.   If he likes the link above, then I will go that route as the novice approach until I learn more.  I am not trying to do this on the cheap.  I just recall always chasing balanced water with my last hot tub.

[RDspaguy]

Well, he will probably jump in here (he gets a notification) since I mentioned him. Then you can ask the chemical guru yourself. Try not to be too excited. He may be a celebrity, but he thinks of himself as a regular old guy just like the rest of us. 😉

[waterbear]

13 hours ago, RDspaguy said:

He may be a celebrity, but he thinks of himself as a regular old guy just like the rest of us. 😉

I'm a superstar! (and who you callin' old? Just because I turned 67 on my birthday last month doesn't make me old!) 🤣🤣🤣

@BB_MikeSeriously, I promise I will put my 2 cents in here on sanitizer choice but I don't have the time right now. I will get back to this in the next day or two!

[BB_Mike]

Great, thanks much.  I am filling it up now and will see what sort of water I have to start out with before I add any chemicals.  Tub is 250 Gallons. So far, the cold tub looks like:

Hardness - 250 ppm

Chlorine - 3 ppm

free chlorine - 1ppm

pH - 6.8 ppm

alkalinity - 40 ppm

stabilizer - between 0 and 50 pm

This is with Clorox brand pool and spa strips.

[BB_Mike]

Getting that Alkalinity up took a lot of product.  3 large caps full spread out over 4 hours.  About 7 tablespoons.  That seems a bit much, and even after that it is still below the 125ppm minimum.  So I put in some pH increase that also read to increase alkalinity.  After that I was on the low side of 125-150 for alkalinity and just right for pH at about 7.5.  I then put in some shock.

I then put in a bromine floater with 1 tablet.  Going to try it out this evening and see how my skin (and back, ha) feel afterwards.

 

[RDspaguy]

11 hours ago, waterbear said:

and who you callin' old?

That was auto correct in action. I typed "ole". Regular ole guy, like the rest of us. 😉

[waterbear]

2 hours ago, BB_Mike said:

that it is still below the 125ppm minimum. 

Where in the world did you see that Total Alkalinity should be a minimum of 125 ppm? You are much better off running it at around 50-70 ppm if you want your pH to stay stable. FWIW, your total alkalinity increaser is nothing more than plain old baking soda (found in the baking aisle of the grocery in a yellow box with an arm holding a hammer on the box), aka sodium bicarbonate, aka sodium hydrogen carbonate and your pH increaser is nothing more than plain old washing soda (found in the laundry aisle in a yellow box with the same arm holding the hammer and it says "Laundry Booster" and "Super Washing Soda" on the box), aka soda ash, aka sodium carbonate which, IMHO, is really only useful for swimming pools that use trichlor tabs in a floater or feeder since trichlor is extremely acidic and causes both TA and pH to crash.  If you need to raise pH quickly (because you accidentally put in too much acid and you need to get the pH up FAST, for example) you are better off using plain old borax (also found in the laundry aisle in a whit3e box with a green stripe on the top and bottom and the words "20 mule team" on the box). Borax will raise pH without having any great effect on TA and is dosed at twice the amount of pH up for the same pH increase. In other words 2 oz of borax will raise the pH about the same as 1 oz of pH up without  sending your TA through the roof!

 

 

[waterbear]

On 3/20/2021 at 9:11 PM, BB_Mike said:

I figure some of this new technology like a copper + zinc ionizer or a mineral stick sitting inside my filter might be a good investment.

NO NO NO NO NO NO NO NO NO NO NO NO NO NO! Stay away from copper/zinc or copper silver! (Still need chlorine with an ionizer, btw, The copper and zinc are basically just algaecides and if you want a copper based algaecide it's much cheaper to buy a bottle of one. BTW, copper is what turns hair green and also stains tubs and pools and they are not  'new technology'

. A "mineral stick" stick is just a cartridge of silver nitrate that is used with either chlorine, or MPS.. Go ahead and call it a 'mineral" sanitzer if it makes you feel warm and fuzzy but we are talking about adding metal to your water. Silver has some activity against bacteria but has very slow kill times and is ineffective against viruses so a fast acting residual sanitizer is still needed. This is either chloirne or MPS AND hot water, which is a sanitizer in conjunction with silver ions.

 

On 3/20/2021 at 9:11 PM, BB_Mike said:

Here is one example:  https://www.swimuniversity.com/hot-tub-mineral-sanitizer/
Seems legit and is what I am leaning towards following.

SO much misinformation. Just don't!

There are 4 EPA approved primary sanitizers for tubs: Chlorine (cheapest but more work. Check out Dichlor/bleach method in the forum) , Bromine (3 step bromine is easy once everything is adjusted but costs more. 2 step or 1 step bromine is as much work as chlorine.), biguinide/peroxide (BaqauSpa, Softsoak, etc.) Non halogen but iis very expensive and has a unique set of problems like clogged filters, 'goo', white water mold (bacterial), and pink slime (also bacterial). Not something I recommend unless you are one of the very rare individual that has a halogen sensitivity and it's been determined that your dermatitis is actually from the chlorine or bromine and NOT from MPS, pH problems,, etc.,  or are one of those people that develop a rash from hot water (more common than you think), and Silver/MPS and HOT water (all three are necessary for this combo to be a sanitizer) and chlorine is still needed weekly as a shock. You can also use silver with chlorine but why bother? Chlorine does just fine on it's own.

[waterbear]

 

Read these:

https://www.poolspaforum.com/forum/index.php?/topic/52522-some-truths-about-ph-and-ta/

https://www.poolspaforum.com/forum/index.php?/topic/52138-bromine-use-in-spas/

https://www.poolspaforum.com/forum/index.php?/topic/23090-dichlorbleach-method-in-a-nutshell/

https://www.poolspaforum.com/forum/index.php?/topic/53108-some-truths-on-bleach-dosing/

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

 

[waterbear]

11 hours ago, BB_Mike said:

Hardness - 250 ppm

Strips measure total hardness (calcium and magnesium). We are interested in only calcium hardness in pool and spa water. Strips cannot measure calcium hardness. You need a liquid reagent test kit for that.  This is a useless measurement.

Chlorine - 3 ppm

I assume this is total chlorine. If this is your fill water it means your water treatment company is adding ammonia with the chlorine to create monochloramine, a common practice.  This also means that your combined chlorine is 2 ppm (Total chlorine - Free chlorine = Combined chlorine)

free chlorine - 1ppm

pH - 6.8 ppm

pH is an absolute scale fro 0 to 14. It is not a part per million measurement.

Strips don't have the resolution to give you any useful pH information since their color chart jumps .6 between blocks. You can get a ballpark idea of the pH but don't use strips to balance the water!

alkalinity - 40 ppm

Strips don't have the resolution to give you any useful Total Alkalinity information. You want a resolution of 10 ppm to make adjustments.

stabilizer - between 0 and 50 pm

IF this is your fill water there should be NO stabilizer (cyanuric acid) in the water Also, you need better resolution to make adjustments. This shows just how 'off' strips can be.  I have found the stabilizer test to be pretty useless in every brand of strip I have ever tried. The stabilizer determines how high you need to run your chlorine. It has no effect in a bromine system and is usually a byproduct of using dichlor as your chlorine source. In a chlorine spa you want a stabilizer level of 30 ppm. You can achieve this by initially chlorinating with dichlor (which adds 9 ppm cyanuric acid for every 10 ppm of FC added) and then switching over to bleach (which does not add stabilizer) once you have added a cumulative FC level of 33 ppm with dichlor. This is the dichlor/ bleach method.

This is with Clorox brand pool and spa strips.

All test strips are basically the same. IF I am not mistaken the Clorox strips are made by Hach/AquaChek.  The ONLY strips I use are LaMotte borate test strips (Much easier to read than the Hach, AquaChek, and Taylor borate strips) and Hach/AquaChek salt titrator strips for salt water chlorine generators.

For testing your water I recommend a Taylor K-2006 FAS-DPD test kit for chlorine or the K-2106 for bromine. FWIW, you can use ANY chlorine test for bromine by using the free chlorine test and multiplying the results by 2.25 to get your total bromine reading. (We are only interested in total bromine in a bromine spa and we don't need to test for stabilizer since it had no effect on bromine.)

[RDspaguy]

26 minutes ago, waterbear said:

NO NO NO NO NO NO NO NO NO NO NO NO NO NO! Stay away from copper/zinc or copper silver! (Still need chlorine with an ionizer, btw, The copper and zinc are basically just algaecides and if you want a copper based algaecide it's much cheaper to buy a bottle of one. BTW, copper is what turns hair green and also stains tubs and pools and they are not  'new technology'

. A "mineral stick" stick is just a cartridge of silver nitrate that is used with either chlorine, or MPS.. Go ahead and call it a 'mineral" sanitzer if it makes you feel warm and fuzzy but we are talking about adding metal to your water. Silver has some activity against bacteria but has very slow kill times and is ineffective against viruses so a fast acting residual sanitizer is still needed. This is either chloirne or MPS AND hot water, which is a sanitizer in conjunction with silver ions.

 

SO much misinformation. Just don't!

There are 4 EPA approved primary sanitizers for tubs: Chlorine (cheapest but more work. Check out Dichlor/bleach method in the forum) , Bromine (3 step bromine is easy once everything is adjusted but costs more. 2 step or 1 step bromine is as much work as chlorine.), biguinide/peroxide (BaqauSpa, Softsoak, etc.) Non halogen but iis very expensive and has a unique set of problems like clogged filters, 'goo', white water mold (bacterial), and pink slime (also bacterial). Not something I recommend unless you are one of the very rare individual that has a halogen sensitivity and it's been determined that your dermatitis is actually from the chlorine or bromine and NOT from MPS, pH problems,, etc.,  or are one of those people that develop a rash from hot water (more common than you think), and Silver/MPS and HOT water (all three are necessary for this combo to be a sanitizer) and chlorine is still needed weekly as a shock. You can also use silver with chlorine but why bother? Chlorine does just fine on it's own.

🙄 The one thing we still disagree on...

I use nature2.

What @waterbearsaid is true, you do still need chlorine (stay away from mps), and silver has slow kill times and... However, there are chlorine resistant bacteria, such as cryptosporidium, and biofilms. With my ozone induced low chlorine levels, I feel that a backup is a good idea.

As for long kill times, I have 20+ hours a day with my spa covered, and no new contaminants entering the water, for that silver to work. And, though some pathogens need more time than that to be destroyed, their ability to reproduce is inhibited much sooner, from what I have read in the course of my research on the subject. This gives your chlorine (and ozone) more time to kill them without a runaway population explosion. This, in theory, means you can have lower chlorine levels, since kill times for chlorine are dependent on ppm. But the contaminants introduced by you entering the water will use up an unknown and variable amount of that chlorine, and 0 FC kills nothing in any amount of time so it's better to have extra.

[waterbear]

2 minutes ago, RDspaguy said:

But the contaminants introduced by you entering the water will use up an unknown and variable amount of that chlorine,

Fun facts (courtesy of Taylor Technologies):

The average person involuntarily urinates about 5─10 mL in pool/spa water.

The average person involuntarily releases about 10─25 mg of fecal matter in pool/spa water.

Fun fact (courtesy of Aqua Magazine):

The average person brings 100 million bacteria into the water. These join other living organisms such as biofilm, parasites, virus, algae, mold, mildew and spores. Then we add swimmer waste such as blood, sweat and tears, urine, saliva, mucous and other bodily fluids

The average spa user sweats up to three pints per hour at 102 degrees Fahrenheit.

Fun fact:

The chemical makeup of sweat and urine are almost identical.

[waterbear]

25 minutes ago, RDspaguy said:

As for long kill times, I have 20+ hours a day with my spa covered, and no new contaminants entering the water, for that silver to work.

IT all goes south as soon as a bather enter the tub. Silver cannot keep up. UV can't keep up, Ozone can't keep up. You need a fast acting residual sanitizer at a high enough level so it's not depleted before doing the job. Notice I said sanitizer and not oxidizer. H2O2 is an oxidizer. MPS is an oxidizer. (However, MPS in HOT water in conjunction with silver nitrate IS considered a residual sanitizer with fast action but IMHO, only marginally so.) Enzymes are NOT sanitizers but might have some effect on biofilms

[BB_Mike]

Looks like I have me some reading to do.  Thanks, waterbear.

Turns out the prior owner had left a jet closed for a long long time.  When I opened it, black stuff shot out.  Not sure if it is pillow foam material or mold/film.  I have something called "spa purge" that he said he ran without the filter each time before he drained it.  So I will be doing a fresh drain/fill in the coming weeks.  In the mean time, I will do some reading and get that test kit ordered.  Between the chemicals I have and the grocery store, I should have a good direction to go in.

 

One review on the taylor 2106 kit said, "Put two tiny caps of dry agent to test Bromine in either 25m or 10m setting. If its pink then there is Total Bromine present. So great, its pink.... no idea if I have 2ppm or 20."

I found that odd.

[waterbear]

15 hours ago, BB_Mike said:

One review on the taylor 2106 kit said, "Put two tiny caps of dry agent to test Bromine in either 25m or 10m setting. If its pink then there is Total Bromine present. So great, its pink.... no idea if I have 2ppm or 20."

I found that odd.

IF you took the time to go to the Taylor Technologies website and look at the videos of how to do the FAS-DPD test you would understand that there is a more to it than just adding DPD powder to your sample. You can use either a 10 ml or 25 ml water sample. 10 ml sample will give a drop equivalent of 1.25 ppm for the K-2106 kit for bromine, 25 ml sample will give a .5 ppm drop equivalent. IF the sample turns pink when you add the DPD powder it means that you have bromine present. tThe next step is to add the FAS titrant drop by drop until the sample turns colorless. You multiply the number of drops by the drop equivalent for your sample size to get your total bromine reading.  SO if you used a 25 ml sample and it took 9 drops to go from pink to colorless you would have 9 x .5 = 4.5 ppm Total bromine. IF you used a 10 ml sample and it took 4 drops to go from pink to colorless then you have 4 x 1.25= 5 ppm Total bromine. The reviews is not wrong in saying that if it turns pink that bromine is present but there is another step to determine the actual level.

The K-2006 kit is similar but there is another reagent involved and a second titration. The first titration gives you Free Chlorine and the second give you the Combined chlorine.

Here are the videos for the K-2006.

https://www.taylortechnologies.com/dc/page/231/k-2006-complete-kit-with-fas-dpd

The two test kits are identical except for the following differences:

The K-2106 for bromine does not include the Cyanuric Acid (chlorine stabilizer) test since cyanuric acid does not stabilize bromine and is not used in a bromine system

The K-2106 does not include reagent R-0003 used in the determination of combined chlorine. With bromine we only test total bromine so it is not needed

The FAS reagent is a different strength to compensate for the higher molecular weight of bromine. With the chlorine test a 10 ml sample give a drop equivaelnt of .5 ppm free chlorine for the first titration and .5 ppm combined chlorine for the second while the bromine test gives a drop equivalent of 1.25 ppm total bromine

Likewise the 25 ml sample give a drop equivalent of .2 ppm for the chlorine test kit and .5 ppm for the bromine kit.

All other tests in the two kits (pH with acid and base demand, Total Alkalinity, and Calcium Hardness) are identical.

FWIW, the K-2006 can be used for testing bromine by only doing the first titation and multiplying the results by 2.25 to get a total bromine reading.

[BB_Mike]

I took the information I found and created a step by step document that fit on a single page.  I am pasting it below.  There are two areas I have questions on:

For TA increasing, what is the formula to know how much baking soda to add?  example:  X tablespoons for Y gallons = +30 ppm increase.

For Shocking, I prefer to use powder versus bleach.  What product should I use?  Also, how much to use for the initial shock?  I am also unsure how often and how much I shock after that?  weekly no matter what?  Or, a tablespoon after each use, but I have to leave the cover off for 30 minutes if I do that.

 

Here is my step by step.  I can attached the document after one last edit to correct any errors.

 

1. Fill the spa with water using a pre-filter.  Then run pumps to circulate water for 10 minutes.

2. Adjust Total Alkalinity (TA) to between 50-70ppm, but no higher than 100. You can raise TA with baking soda.  Wait 30 minutes between adding baking soda and re-testing. 

Wait 30 minutes with pumps running.

3. Adjust pH to between 7.4 and 7.8.  If pH is above 8.0, use dry acid to lower pH.  If pH is below 7.2, use borax from the laundry aisle to raise pH..  Note: “pH up” will make your TA go up as well.

Wait 30 minutes with pumps running.

4. If calcium hardness is below 130 ppm, raise it to 130-150ppm. If it is above 400 then add an anti stain and scale or calcium reducer to the spa. Any number between 130-400 is ok.

Wait 30 minutes with pumps running.

5. Add 1/2 oz of sodium bromide per 100 gallons of water (1.25oz for 250G) to create the bromide reserve in the water.  Do not use a one step bromine product that is a mixture of dichlor and only a little bit of sodium bromide.  It should only contain sodium bromide (and water if in liquid form).

Wait 30 minutes with pumps running.

6. Shock by adding either:

1. Unscented liquid chlorine bleach:   Per each 100 gallons of spa water add either 2.5 oz (5 tablespoons) if bleach is 5.25% or 2 oz (4 tablespoons) if bleach is 6%.

2. Shock Powder:   What product to use and how much?  58.2% Sodium Dichloro-s-Triazinetrione

7. After shocking, allow spa to run with cover off for 2 hours.  Then close the cover and allow the spa to come up to temperature.

8. Measure bromine to ensure it is below 10ppm.  If over, remove cover and run pumps.

9. Place bromine tablets into the floater and adjust dispenser daily until bromine = 4-6ppm.

10. DAILY until stable:  Check your pH and bromine levels once a day until bromine is stable. 

1. If pH is not between 7.2 and 8.0 then adjust.  WAIT 30 MINUTES 

2. If bromine is low add a few tablespoons of bleach and retest until it is above 4 ppm. This should only take a few seconds to happen.  Then adjust the floater to disperse more bromine.

3. If bromine is high, remove cover, remove floater, run pumps.  Close down the floater to disperse less bromine.

11. WEEKLY -  Keep pH between 7.2 -8.0 and if adjustments are made, then shock the spa with bleach. If hardness is above 400ppm, then add anti scale or calcium reducer.

12. MONTHLY -  check and adjust TA, then calcium then pH, then shock spa.

13.  After 3 months, use spa purge to clean prior to draining.  Clean filters.  Go back to step 1.

[d.sebens]

I would probably edit it to add using the air injectors and blower when doing ph adjustments as it will help “stabilize?” An equilibrium between the current ta and ph.  I may of worded that wrong but basically if your ta is 100 and your ph is 7.0, run the pumps with all the air injection you have. Your ta will drop as ph rises up.

[waterbear]

23 minutes ago, d.sebens said:

if your ta is 100 and your ph is 7.0, run the pumps with all the air injection you have. Your ta will drop as ph rises up.

Not quite. Adding acid lowers TA. Period. Aeration raises pH with NO impact on TA. ANY chemical method of raising pH WILL also raise TA. IF you are trying to lower pH you add acid to no lower than 7.0 (anything lower could potentially harm the tub and equipment) and then aerate to bring the pH up.  At first A doesn't move much but as you repeat this process of adding acid and aerating you will eventually get your pH to your desired target.

Read this:

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

 

[d.sebens]

Just now, waterbear said:

Not quite. Adding acid lowers TA. Period. Aeration raises pH with NO impact on TA. ANY chemical method of raising pH WILL also raise TA. IF you are trying to lower pH you add acid to no lower than 7.0 (anything lower could potentially harm the tub and equipment) and then aerate to bring the pH up.  At first A doesn't move much but as you repeat this process of adding acid and aerating you will eventually get your pH to your desired target.

Read this:

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

 

Ohh my bad.  So does the ph increase from air come directly from the air being pumped in?  I thought that TA would lower slowly as ph goes up with acid addition and areation. You are the master of this, I’m just trying to understand the process. 
 

I would just refrain from the advice and just let you respond. 

[waterbear]

read this:

https://www.poolspaforum.com/forum/index.php?/topic/52522-some-truths-about-ph-and-ta/

and reread the link above where I explain and answer your question. It has nothing to do with air being pumped in. pH rise occurs as CO2 gases off and will also occur with no aeration. Aeration just speeds up the process. Think of an opened bottle of seltzer. If you let it sit long enough it goes flat (CO2 outgasses). IF you shake the bottle (which aerates it) it goes flat much faster.  CO2 dissolved in water is basically carbonic acid (close enough, anyway) as the CO2 leaves the system the amount of carbonic ACID in the system is lowered (operative word here is ACID) If you lower the acid in the water the pH will rise. (IF you test the pH of a newly opened bottle of seltzer it will be acidic. If you retest after it has gone flat the pH has gone up since it's now just a bottle of water.

[d.sebens]

So the act of lowering the ta has already pushed the co2 into the water thus lowering ph?  So the time involved is just waiting for the co2 to come out?

[waterbear]

Think of a children's  see saw on one side you have bicarbonate ions, on the other carbonic acid. The see saw is level (the chemical equation is in equilibrium) If you add any acid you are adding hydrogen ions that react with the bicarbonate to make carbon dioxide gas and water. The CO2 dissolved in the water making carbonic acid. There is now less bicarbonate and more carbonic acid so the side of the see saw with the carbonic acid goes down (the pH drops) However, the see saw (chemical equation) is no longer in equilibrium  and CO2 outgasses so there is less CO2 in the system. As the CO2 leaves there is less carbonic acid and the see saw goes back to level as the amount of carbonic acid matches the now lower amount of bicarbonate in the system. Bicarbonate is what we measure when we measure TA.

The act of adding acid to lower pH converts bicarbonate to carbonic acid. This act alone lowers the TA If we allow the carbonic acid to leave the system by outgassing the amount of acid in the system is less and the pH rises. Since we have removed carbonation the bicarbonate cannot reform and the TA can't rise. IF instead we add a chemical to cause the pH to rise then the chemical reaction will form water and bicarbonate ions once again and the TA rises with the pH. IF the chemical we are adding is pH up (sodium carbonate) we are also adding addition bicarbonate ions to the water and causing the TA to rise higher than it was originally. (carbonate ions don't exist in water at normal pool and spa pH ranges and become bicarbonate).

[d.sebens]

Thank you for the explanation I didn’t realize what was changing to go into an equilibrium when changing TA and ph.