When to add more bromine?

[carl333]

Ok, I've added bromine, added activator, took a few dips and naturally the disinfectant level drops. Ok so I add more activator every day or so to bring it up to a safe level. I've read just to continue to add the activator until the next water change. Doesn't bromine itself consume over time? Do I need to add more once in a while?

 

[Kiss4aFrog]

Re: Wneh to add more bromine?

Welcome to the forum

This might be helpful : http://www.troublefreepool.com/threads/84-How-do-I-use-Bromine-in-my-spa-(or-pool)

 

[chem geek]

Re: Wneh to add more bromine?

Note that there are ways to maintain a background level of bromine in between soaks by either using bromine tabs in a floating dispenser or having a bromide bank (created by adding sodium bromide) and having an ozonator. It's after your soak that you add additional oxidizer to handle your bather waste, especially if you soak infrequently. If you soak regularly every day, you might be able to tune your ozonator on-time or bromine dispenser opening or both to provide enough bromine for your soaks.

 

[carl333]

Re: Wneh to add more bromine?

Note that there are ways to maintain a background level of bromine in between soaks by either using bromine tabs in a floating dispenser or having a bromide bank (created by adding sodium bromide) and having an ozonator. It's after your soak that you add additional oxidizer to handle your bather waste, especially if you soak infrequently. If you soak regularly every day, you might be able to tune your ozonator on-time or bromine dispenser opening or both to provide enough bromine for your soaks.

Tabs are expensive and I don't have an ozonator. I'd like to continue to use sodium bromide in granular form and a separator activator. Does both the activator and sodium bromide deplete after soaks or do I just continue to add MPS/chlorine to bring it to a safe level?

 

[Kiss4aFrog]

Re: Wneh to add more bromine?

You add the sodium bromide to the water to the proper concentration for the size (gal) of your spa. This is done after changing the water and is your bromine reserve that is used to make sanitizer. You shouldn't need to add it again.
You need to add oxidizer on a regular basis (usually, chlorine, MPS, or ozone, or a combination of them) to oxidize the bromide ions into hypobromous acid, your active sanitizer. It's pretty easy but does require a bit of attention daily to maintain a 4-6 ppm bromine level in the water.
What is it you are using as an "activator" ??

 

[chem geek]

You might have some slow loss of bromide through carry-out (i.e. water dilution) and from some bromine outgassing, and there can be some converted to bromate (though that's mostly from an ozonator and not so much if you use chlorine or MPS as the "activator").

So in your situation, you'll have to add an oxidizer (what you call an "activator") regularly, not just after each soak but in between soaks if you don't soak every day. You'll have to test to see how frequently that will need to be. It might be every other day or perhaps twice a week but I'd be surprised if the bromine lasted for a week unless the water temperature were turned down. You can probably figure on a bromine loss similar to that of chlorine which is around 15-25% per day. So that's a 39-58% loss after 3 days and a 68-87% loss over a week if the water is kept fairly hot (say 95ºF or more).

 

[carl333]

Re: Wneh to add more bromine?

You add the sodium bromide to the water to the proper concentration for the size (gal) of your spa. This is done after changing the water and is your bromine reserve that is used to make sanitizer. You shouldn't need to add it again.
You need to add oxidizer on a regular basis (usually, chlorine, MPS, or ozone, or a combination of them) to oxidize the bromide ions into hypobromous acid, your active sanitizer. It's pretty easy but does require a bit of attention daily to maintain a 4-6 ppm bromine level in the water.
What is it you are using as an "activator" ??

I used 1.25 cups this morning of chlorine bleach. 300 gal. tub. Tested with K-2106 several hours later, and no reading.

Discouraged, I added more sodium bromine and MPS a few moments ago. Perhaps I should have just added more MPS or more chlorine and check for a reading before adding more bromine. Your thoughts?

 

[Kiss4aFrog]

How much sodium bromine did you add ??
How often do you change your water ??
If the last time you changed the water you added 1.5oz of sodium bromide then you have enough to sanitize IF you use the correct amount of oxidizer. Adding more sodium bromide doesn't do any good as you should already have more than enough. You need to add the oxidizer to convert it into a sanitizer.

 

[carl333]

You might have some slow loss of bromide through carry-out (i.e. water dilution) and from some bromine outgassing, and there can be some converted to bromate (though that's mostly from an ozonator and not so much if you use chlorine or MPS as the "activator").

So in your situation, you'll have to add an oxidizer (what you call an "activator") regularly, not just after each soak but in between soaks if you don't soak every day. You'll have to test to see how frequently that will need to be. It might be every other day or perhaps twice a week but I'd be surprised if the bromine lasted for a week unless the water temperature were turned down. You can probably figure on a bromine loss similar to that of chlorine which is around 15-25% per day. So that's a 39-58% loss after 3 days and a 68-87% loss over a week if the water is kept fairly hot (say 95ºF or more).

15-25% loss of bromine per day? Why am I reading that it is not necessary to add bromine between fills then? Do we have 2 camps? Now I'm totally confused. To add or not to add. Set me straight please.

 

[chem geek]

You don't have to add more sodium bromide after first adding it after a water change, but that is not the same as adding an oxidizer to create more bromine. Bromine gets used up even when you are not using the spa, but it reverts back to bromide ion. So you need to re-activate it using an oxidizer to convert bromide back to bromine.

So I repeat -- you add the sodium bromide once after a refill. You add an oxidizer regularly after every soak and as needed in between soaks.

As for your adding 1.25 cups of what I presume to be 8.25% bleach to a 300 gallon tub, that would be 27 ppm FC in a chlorine test or 61 ppm Total Bromine in a bromine test (the units of measurement are different for chlorine and bromine). I suspect that this very high amount is bleaching out your DPD indicator dye. Did you see a "flash of pink" when you added the DPD powder? If so, add more DPD powder (another scoop or two) to see if you get a color. If it's truly zero, then you have something in your tub consuming a lot of bromine. Also note that chlorine and bromine tests cannot distinguish between chlorine and bromine. So even if you did not have enough bromide in the water to make bromine, the chlorine you added should still have registered on the test.

 

[Kiss4aFrog]

Just in case it isn't obvious ... bromide and bromine are not the same.

You need to add the oxidizer to convert it (bromide) into a sanitizer (bromine).

Maybe you have a build up of organic matter in the pipes since you haven't been keeping a proper level of sanitizing bromine.
Might be time to thoroughly clean out the tub. http://www.youtube.com/watch?v=XY_tBzd4tTg

 

[chem geek]

If this is a new tub that you've never decontaminated before, then you can use Ahh-Some to remove greases/oils from the factory as well as any biofilms that may have formed from wet-testing of the spa. You would use this product just before you replace the water.

 

[carl333]

You don't have to add more sodium bromide after first adding it after a water change, but that is not the same as adding an oxidizer to create more bromine. Bromine gets used up even when you are not using the spa, but it reverts back to bromide ion. So you need to re-activate it using an oxidizer to convert bromide back to bromine.

So I repeat -- you add the sodium bromide once after a refill. You add an oxidizer regularly after every soak and as needed in between soaks.

As for your adding 1.25 cups of what I presume to be 8.25% bleach to a 300 gallon tub, that would be 27 ppm FC in a chlorine test or 61 ppm Total Bromine in a bromine test (the units of measurement are different for chlorine and bromine). I suspect that this very high amount is bleaching out your DPD indicator dye. Did you see a "flash of pink" when you added the DPD powder? If so, add more DPD powder (another scoop or two) to see if you get a color. If it's truly zero, then you have something in your tub consuming a lot of bromine. Also note that chlorine and bromine tests cannot distinguish between chlorine and bromine. So even if you did not have enough bromide in the water to make bromine, the chlorine you added should still have registered on the test.

Ok, I think I may have figured it out. I just tested my water by adding 4 dippers and no color change. Usually I would dump out the sample and add more sanitizer. I forgot this time and after 30 minutes, it turned a rosy pink. The DPD is about 1 year old in a K-2106 kit. Should I be seeing an immediate color change or is waiting 30 min. giving me a false reading?

- - - Updated - - -

sorry, I am using the terms bromine and bromide incorrectly but I know the difference. Tks for pointing that out. I think my DPD testing may give me an incorrect reading. See above

 

[Kiss4aFrog]

If you know the difference between the two why are you still tossing in the sodium bromide ??

 

[chem geek]

Ok, I think I may have figured it out. I just tested my water by adding 4 dippers and no color change. Usually I would dump out the sample and add more sanitizer. I forgot this time and after 30 minutes, it turned a rosy pink. The DPD is about 1 year old in a K-2106 kit. Should I be seeing an immediate color change or is waiting 30 min. giving me a false reading?

That is very strange. The color should develop immediately. Perhaps you should call Taylor Technologies technical support about this.