How much bromine do I need? How much chlorine do I need?

[Snoochers]

I've got a 9200 litre spa/pool thing and it is sanitized with bromine and I have several questions:

• How much bromine should be in the water? Is it about 3ppm?
• How do I control how much bromine is in the water? Do I add a big batch to build the "bank" and leave it at that for weeks or months or should I use a floating dispenser thing?
• If the dispenser, then how much should I put in there? I filled it 50-75% full last week and I tested my water with my Taylor test this morning and I got 13ppm total bromine which seems like way too much. This is with minimum openings.
• My bromine tablets seem to also include chlorine, maybe 25-30%. Do I still need to add extra chlorine to activate the bromine?
• How much chlorine should be in the water? 3ppm? Or do I add chlorine as a proportion of bromine somehow?

Some of these are somewhat basic questions maybe and I've read the Taylor book but I'm still not sure how to manage the bromine perfectly.

 

[Newdude]

Hey snoochers and Welcome !!

It's either/or. Have a read.

How do I use Bromine in my Spa or Hot Tub?

Originally Posted by waterbear There is a lot of misinformation on the proper way to use Bromine so I hope this primer is helpful. First, you need to establish a bromide reserve in the water. Bromine tablets can do it by themselves but it can take literally weeks until enough dissolves. Some...

www.troublefreepool.com

How do I use Chlorine in my Spa or Hot Tub?

If you have a question about any information within this Sticky, please start a new thread for yourself where you will receive very quick responses to your specific questions. Thank you! Introduction There are two main things to consider when maintaining your hot tub water, Water Balance and...

www.troublefreepool.com

 

[Snoochers]

Hey snoochers and Welcome !!

It's either/or. Have a read.

How do I use Bromine in my Spa or Hot Tub?

Originally Posted by waterbear There is a lot of misinformation on the proper way to use Bromine so I hope this primer is helpful. First, you need to establish a bromide reserve in the water. Bromine tablets can do it by themselves but it can take literally weeks until enough dissolves. Some...

www.troublefreepool.com

How do I use Chlorine in my Spa or Hot Tub?

If you have a question about any information within this Sticky, please start a new thread for yourself where you will receive very quick responses to your specific questions. Thank you! Introduction There are two main things to consider when maintaining your hot tub water, Water Balance and...

www.troublefreepool.com

Sorry I don't quite understand. I have a bromine system but my understanding is that bromine pools require to be activated, often with chlorine. So I do need chlorine (or something), do I not?

 

[Newdude]

I have a bromine system but my understanding is that bromine pools require to be activated, often with chlorine. So I do need chlorine (or something), do I not?

Apologies. We're conditioned to newbs often thinking the 2 are the same. They're 2 unique paths which share some similarities. Lemme call you @Mdragger88 who is better at bromine than me.

 

[Mdragger88]

Its all thoroughly explained in the bromine guide posted above so be sure to read through that a few times.
You need some sort of oxidizer to activate the bromide bank & turn it into bromine.
We recommend using liquid chlorine for this.
You want to maintain 4-6ppm total bromine. Your tabs do kinda “activate themselves” because of their chlorine content but you may find that you need to add some additional chlorine to keep the total br level up after use. & you will need to shock weekly so you can use liquid chlorine for that as well.
Your testing will be your guide.

 

[Snoochers]

Its all thoroughly explained in the bromine guide posted above so be sure to read through that a few times.
You need some sort of oxidizer to activate the bromide bank & turn it into bromine.
We recommend using liquid chlorine for this.
You want to maintain 4-6ppm total bromine. Your tabs do kinda “activate themselves” because of their chlorine content but you may find that you need to add some additional chlorine to keep the total br level up after use. & you will need to shock weekly so you can use liquid chlorine for that as well.
Your testing will be your guide.

You say "total bromine", which is what my Taylor test is testing for right? Isn't that value unaffected by how much chlorine there is? Or does adding chlorine increase total bromine? That is the part I don't understand I guess.

Also, why does shocking need to happen? I thought the bromine kept things sanitized enough.

 

[Mdragger88]

You say "total bromine", which is what my Taylor test is testing for right?

Yes- that is the only thing you can test for.
You cannot test the sodium bromide level.
Sodium bromide is converted to total bromine once activated by an oxidizer.
Your bromine level will only increase as much as is activated. The rest of the sodium bromide will be in reserve (your bank).

Isn't that value unaffected by how much chlorine there is? Or does adding chlorine increase total bromine? That is the part I don't understand I guess.

Yes & yes - example: if you put in a small amount of chlorine it will only increase the total Bromine level by a small amount, no matter how much sodium bromide you have in the water.
ie- 1 ppm worth of liquid chlorine will result in a 2.25 ppm total bromine increase (if you have enough sodium bromide in the water to be activated).

Also, why does shocking need to happen? I thought the bromine kept things sanitized enough.

In theory it shouldn’t be necessary, if the bromine is maintained properly (4-6ppm) around the clock.

 

[Snoochers]

Yes- that is the only thing you can test for.
You cannot test the sodium bromide level.
Sodium bromide is converted to total bromine once activated by an oxidizer.
Your bromine level will only increase as much as is activated. The rest of the sodium bromide will be in reserve (your bank).

Yes & yes - example: if you put in a small amount of chlorine it will only increase the total Bromine level by a small amount, no matter how much sodium bromide you have in the water.
ie- 1 ppm worth of liquid chlorine will result in a 2.25 ppm total bromine increase (if you have enough sodium bromide in the water to be activated).

In theory it shouldn’t be necessary, if the bromine is maintained properly (4-6ppm) around the clock.

WOW thank you that’s very useful. So the other day I had 13ppm total bromine because I had a healthy bank and added too much chlorine I guess?

And if I add a chlorine product at 33% efficiency I need to add 3ppm to achieve 1ppm chlorine correct?

So if I want 4ppm bromine and have a healthy bank of bromine then I can add 1.78ppm of chlorine (or [email protected] efficiency).

Is there some kind of formula to figure out how quickly activated bromine will fade away?

I’ll be testing and trying to base as much of this as possible on my own results but it’s good to start with solid foundations.

 

[Mdragger88]

I’m not following the 33% efficiency thing

 

[Mdragger88]

There’s no formula for sanitizer demand during use or standby.
You must test before & after use & before & after standby to determine what that looks like in your tub with your bather loads. Every tub is different.