Is this laundry bleach okay for shocking a bromine spa?

spada

Member
Apr 4, 2017
10
Malaga
I bought these two laundry bleaches at the store, the first one is powder and the second is liquid (if it matters).
"Blanqueantes oxigenados" translates to "Oxygen bleaches" on google translate and I can't find sodium hypochlorite (google translate: hipoclorito de sodio) written anywhere.
Are any one usable as a shocker in a bromine spa?

Powder:
powder_bleach.jpg

Liquid:
liquid_bleach.jpg
 

domct203

Bronze Supporter
LifeTime Supporter
TFP Guide
Jun 3, 2015
3,959
CT
I don't think either of those contain sodium hypochlorite either, and would not put them in my pool or spa.

Can you not get regular bleach where you are? (is it Spain?).
 

Donldson

TFP Expert
LifeTime Supporter
In The Industry
Jun 12, 2009
3,347
NW Ohio
Oxygen bleach is almost certainly sodium percarbonate, which is not what you are looking for. Although pure sodium percarbonate is useful in very specific pool situations, the laundry version has additional ingredients added and you shouldn't use it in your spa.
 

spada

Member
Apr 4, 2017
10
Malaga
Thanks for the responses! I went to a pool store nearby and got recommended and bought "SpaCare Oxicare gr (Oxigeno activo)", product link: Oxicare granulado

Google translate on the above link says:
Rapidly dissolving active oxygen for disinfection and maintenance of chlorine-free water.
It also acts as a Bromine Activator.


I have another question regarding bromine levels. The guy at the pool store basically told me "keep the bromine levels as low as possible as long as the water is clear". I understand his reasoning about the bromine being bad for the skin but I still want to confirm it here with all you experts :) My bromine levels are as low as 0.5-1.5, is that okay or too low? I got 3 small children using the spa pretty much every day after day care, so I don't want too much bromine if I don't have to.
 

MPurcell

Well-known member
Feb 17, 2017
105
Dahlonega, Georgia
The recommendation for bromine in a spa is 4-6 ppm. See the sticky above How do I use Bromine in my spa (or pool)? We don't have small children, just me and my wife, but I found that the water didn't stay perfectly clear when I was targeting 4-6 ppm so I have been keeping mine in the range of 8-10 ppm pre soak. Also, if you keep the sanitizer level very low, it can easily go to zero while the tub is in use, and the possibility of bacteria in the water is much more dangerous than a slightly elevated bromine level.

How are you testing bromine level? If you are using a chlorine test kit, then 0.5-1.5 ppm (chlorine scale) would be 1.125-3.375 ppm (bromine scale). Still a little low, but closer to the 4-6 ppm recommended.
 

spada

Member
Apr 4, 2017
10
Malaga
I use the 3 step method from the Bromine sticky thread. I didn't (and still don't) have any sodium bromide however but I crushed 6 Bromine tablets after filling. Active oxygen seem to be another word for MPS--potassium monopersulfate so even though it was expensive it's usable :) The pool store said to use a spoon MPS after each soak, should I just go with the once a week method from the Bromine sticky thread?

I'm testing the Bromine with a Taylor K-2006, using 25ml and counting 0.5 ppm per drop. Should I crush a few Bromine tablets, just add more tablets to the floater and wait or do I have to buy sodium bromide to get the Bromine levels up a notch?
 

MPurcell

Well-known member
Feb 17, 2017
105
Dahlonega, Georgia
Okay, your bromine levels of 0.5 to 1.5 ppm are lower than the recommended levels of 4 to 6 ppm. Since you don't have access to sodium bromide to build a bromide bank, and have crushed 6 of the 1" BCDMH tabs, you may not have as much as 50 ppm bromide bank, but you will have some bromide bank, maybe at least 10 to 15 ppm, and that will increase as you dissolve additional tabs in the floater. If you have 15 ppm of sodium bromide in the water, you can increase your bromine level (hydrobromous acid) to 15 ppm by adding the right amount of MPS oxidizer, which will convert the sodium bromide into hydrobromous acid almost instantly.

You can use pool math to figure out how much MPS to add. Pool math does not have a setting for bromine, and it does not have an option for MPS oxidizer. However, you can use chlorine units and convert back and forth between chlorine and bromine. I have found by experimentation that 1 teaspoon of 43% MPS (this is the standard in the USA) is roughly equivalent to 1/2 oz of 8.25% bleach.

So you can do an experiment to test this out. I don't see the volume of your spa, so you will have to set the pool math calculator for your spa volume first. Now, take a bromine level with your test kit. Be sure to let the sample water cool down below 90 deg F before you test. Let's say your level is 1.5 ppm and you want to test raising it to 6.0 ppm. Convert to chlorine equivalent by dividing by 2.25. 1.5 ppm bromine = 0.666 ppm chlorine. Put that in pool math in the "Now" column for FC. 6.0 ppm bromine = 2.66 ppm chlorine. Put that in pool math in the "Target" column for FC. On the top line, put 8.25% for the strength of the bleach. Let's say your spa is exactly 400 gallons. The result will read "Add 1.2 oz of 8.25% weight bleach." Now convert that measure of bleach to tsp of MPS. 1.2 oz would be roughly 2-1/2 teaspoons of MPS. Put that amount of MPS in the spa and turn on the jets and air to stir the water. Now take another reading with your test kit. If you have an adequate bromide bank, your reading should be somewhere close to 6 ppm. Remember to use your actual water volume and do your own calculation.

I suppose if your kitchen measures are metric, you will have to do some additional conversions.

With the 3 step method, you should add oxidizer (MPS) after each use of the spa. The amount you add will depend on the number of bathers and the time in the tub. Also, adults would produce more bather waste (usually) than children. The idea is to exactly neutralize the bather waste added to the tub, so that the bromine ppm after soaking would be roughly the same as the bromine ppm before soaking. The floater should be set then to keep the bromine level as close to the same as possible between soaks.

I found that for my wife and I, soaking in 215 gallons of water at 101 deg F for 30 minutes, I need to add 1 to 1-1/2 oz of 8.25% bleach, or 2 teaspoons to 1 tablespoon of MPS, to neutralize the bather waste.

Note: About minimum sanitizer levels. The Chlorine/CYA Chart indicates that with no CYA in the water, the minimum free chlorine level for safe sanitization is very low. However, there is a footnote that states: "A minimum FC level is needed as a "reserve" for usage so in practice at least 2 ppm FC is required even at low CYA levels. The table above shows the amount needed for disinfecting chlorine for equivalent killing power (rates), but does not take into account the amount needed in reserve to prevent getting used up as this varies by pool." Now, this information is for pools and not spas, and for chlorine and not bromine. However, a minimum of 2 ppm of FC would be equivalent to 5 ppm of bromine. So if pools and spas are even roughly equivalent, it would seem that 5 ppm bromine would be a safe minimum. It's probably a little lower than that since the recommendation is for 4 to 6 ppm, but it gives you an idea of how inadequate 0.5 to 1.5 ppm bromine would be.
 

TheBraLady

Gold Supporter
Jun 8, 2015
178
Concord, NC
Okay, your bromine levels of 0.5 to 1.5 ppm are lower than the recommended levels of 4 to 6 ppm. Since you don't have access to sodium bromide to build a bromide bank, and have crushed 6 of the 1" BCDMH tabs, you may not have as much as 50 ppm bromide bank, but you will have some bromide bank, maybe at least 10 to 15 ppm, and that will increase as you dissolve additional tabs in the floater. If you have 15 ppm of sodium bromide in the water, you can increase your bromine level (hydrobromous acid) to 15 ppm by adding the right amount of MPS oxidizer, which will convert the sodium bromide into hydrobromous acid almost instantly.

You can use pool math to figure out how much MPS to add. Pool math does not have a setting for bromine, and it does not have an option for MPS oxidizer. However, you can use chlorine units and convert back and forth between chlorine and bromine. I have found by experimentation that 1 teaspoon of 43% MPS (this is the standard in the USA) is roughly equivalent to 1/2 oz of 8.25% bleach.

So you can do an experiment to test this out. I don't see the volume of your spa, so you will have to set the pool math calculator for your spa volume first. Now, take a bromine level with your test kit. Be sure to let the sample water cool down below 90 deg F before you test. Let's say your level is 1.5 ppm and you want to test raising it to 6.0 ppm. Convert to chlorine equivalent by dividing by 2.25. 1.5 ppm bromine = 0.666 ppm chlorine. Put that in pool math in the "Now" column for FC. 6.0 ppm bromine = 2.66 ppm chlorine. Put that in pool math in the "Target" column for FC. On the top line, put 8.25% for the strength of the bleach. Let's say your spa is exactly 400 gallons. The result will read "Add 1.2 oz of 8.25% weight bleach." Now convert that measure of bleach to tsp of MPS. 1.2 oz would be roughly 2-1/2 teaspoons of MPS. Put that amount of MPS in the spa and turn on the jets and air to stir the water. Now take another reading with your test kit. If you have an adequate bromide bank, your reading should be somewhere close to 6 ppm. Remember to use your actual water volume and do your own calculation.

I suppose if your kitchen measures are metric, you will have to do some additional conversions.

With the 3 step method, you should add oxidizer (MPS) after each use of the spa. The amount you add will depend on the number of bathers and the time in the tub. Also, adults would produce more bather waste (usually) than children. The idea is to exactly neutralize the bather waste added to the tub, so that the bromine ppm after soaking would be roughly the same as the bromine ppm before soaking. The floater should be set then to keep the bromine level as close to the same as possible between soaks.

I found that for my wife and I, soaking in 215 gallons of water at 101 deg F for 30 minutes, I need to add 1 to 1-1/2 oz of 8.25% bleach, or 2 teaspoons to 1 tablespoon of MPS, to neutralize the bather waste.

Note: About minimum sanitizer levels. The Chlorine/CYA Chart indicates that with no CYA in the water, the minimum free chlorine level for safe sanitization is very low. However, there is a footnote that states: "A minimum FC level is needed as a "reserve" for usage so in practice at least 2 ppm FC is required even at low CYA levels. The table above shows the amount needed for disinfecting chlorine for equivalent killing power (rates), but does not take into account the amount needed in reserve to prevent getting used up as this varies by pool." Now, this information is for pools and not spas, and for chlorine and not bromine. However, a minimum of 2 ppm of FC would be equivalent to 5 ppm of bromine. So if pools and spas are even roughly equivalent, it would seem that 5 ppm bromine would be a safe minimum. It's probably a little lower than that since the recommendation is for 4 to 6 ppm, but it gives you an idea of how inadequate 0.5 to 1.5 ppm bromine would be.

Oh. My. Goodness. I can not thank you enough for this post. I don't know why, but I have always been a little fuzzy on all this for my spa. You have explained it perfectly. Thank you!!
 

spada

Member
Apr 4, 2017
10
Malaga
I can't do anything but agree with TheBraLady, thank you MPurcell! I've read the Bromine sticky thread probably 10 times or more by now but totally missed the relationship between MPS and Bromine levels and how you use it to bump up the Bromine after each use.
 

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