Just finished draining and refilling a 200gal dream maker spa. Added 1oz of 99% sodium bromide per the package instructions. PH 7.6, TA 60, CH 110. When I try to check total Bromine my test kits (all 3) show 0ppm. Test kits are Taylor K-1001 (used for quick daily checks) Taylo K-2106 (used for weekly/bi-weekly tests) and pool master 5way kit (first kit I purchased). I've never had a zero reading before after refill so I'm kinda puzzled. Any help would be appreciated.
Odd bromine readings after refill
- Thread starter SJ781
- Start date
- May 23, 2015
- 25,258
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
You have to add an oxidizer to convert bromide to bromine. How do you normally add bromine?
I use HTH Brom-Start. The directions say to add .5oz/100gal of water to establish a 30ppm bromide reserve. In the past it has shown up when I tested. My older test kits didn't read that high so I had to assume 1oz was correct. That's why I purchased the K-2106 kit thinking it would show the ppm of reserve. I added 4oz of LC and it now shows a reading of 17.5ppm. I guess I'm still confused about Bromide, Bromine (free and combined) and how to measure them.
Thanks.
Thanks.
- May 23, 2015
- 25,258
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
You may want to review this thread on how to operate a bromine hot tub - How do I use Bromine in my spa (or pool)?)
Bromide is the reduced salt form of bromine. In other words, sodium bromide is similar to sodium chloride, it's just a harmless, non-reactive salt. When you add an oxidizer to your hot tub water that has bromide salts in it, the bromide gets converted to bromine which is a powerful chemical sanitizer and oxidizer. So, when you add liquid chlorine (aka, bleach) to a body of water with bromide in it, the bromide gets converted to bromine (what you want) and the chlorine gets converted to chloride (useless salt). You need to keep adding chlorine to your tub or float bromine tablets that contain both bromine and chlorine in order to constantly regenerate and maintain a residual bromine level as it gets used up killing bacteria and oxidizing bather waste.
A test kit will never detect bromide, it is only sensitive to the sanitizing form, bromine. If you did add bromide to the tub and detected bromine then you either had some residual chlorine in the water OR, quite possibly, your tub has an ozonator built into it. Ozone can act like chlorine in that it will convert bromide to bromine.
Does your tub have an ozonator?
Bromide is the reduced salt form of bromine. In other words, sodium bromide is similar to sodium chloride, it's just a harmless, non-reactive salt. When you add an oxidizer to your hot tub water that has bromide salts in it, the bromide gets converted to bromine which is a powerful chemical sanitizer and oxidizer. So, when you add liquid chlorine (aka, bleach) to a body of water with bromide in it, the bromide gets converted to bromine (what you want) and the chlorine gets converted to chloride (useless salt). You need to keep adding chlorine to your tub or float bromine tablets that contain both bromine and chlorine in order to constantly regenerate and maintain a residual bromine level as it gets used up killing bacteria and oxidizing bather waste.
A test kit will never detect bromide, it is only sensitive to the sanitizing form, bromine. If you did add bromide to the tub and detected bromine then you either had some residual chlorine in the water OR, quite possibly, your tub has an ozonator built into it. Ozone can act like chlorine in that it will convert bromide to bromine.
Does your tub have an ozonator?
No ozone generator. I'm guessing previously there was residual Bromine in the tub when I cleaned it. That's what threw me this time. I've read that sticky several times and thought I understood it. Before, I would drain it clean the interior of the tub and refill it (residual was in the piping). This time due to a prolonged power outage I drained it, vacuumed out the piping, cleaned the interior and refilled (no residual in the piping). I think I have a better handle on it now. Thanks
- May 23, 2015
- 25,258
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
You should consider using a hot tub plumbing purge product at some point in the future. Many hot tub owners on TFP use Ahh-some to purge out their plumbing systems once per year. It is very effective at removing trapped oils, bacterial biofilms and the general scum buildup that occurs in a hot tub plumbing as there is no easy way to effectively drain the entire plumbing system. And yes, if you did not flush out your tub lines with fresh water, then there was probably residual bromine in your tub.