Relationship Between Bromine And Shock

[Tom Kirshbaum]

I've been trying bromine, following Water Bear's three-step process. Each day or two, whether I use the tub or not, the bromine reading (yes, I'm using test strips) drops to hardly any color change on the strip, so I add 1.75 tsp of non-chlorine shock (215 gal. tub) and the bromine level goes back up to normal. But to get this I have to shock every day. Is this because my floater isn't open enough? If the shock takes the bromine level back up, doesn't that mean that there's enough bromine in the water? If so, won't opening the floater more cause bromine levels that are too high when Ii do shock?

As you can see, I'm confused

Tom

[chem geek]

Unless you use the spa infrequently, it is unlikely for the bromine tabs in the floater to output enough bromine to handle your bather waste. Yes, you could turn up the bromine floater to output more bromine, but it may have to result in starting your soak with a higher bromine level and that might be unpleasant. You can try that if you want and see how that works for you. Normally though the bromine tabs are just there to provide a background level of bromine in between soaks, especially if you are not soaking every day. You then add an oxidizer after your soak to create more bromine from the bromide bank to oxidize your bather waste. Think of the convenience of bromine having to do with not having to do anything in between, say, weekly soaks. It doesn't completely automate dosing for you for every soak.

Now those spas with an ozonator can sometimes get away without having to add an additional oxidizer after every soak, depending on the bather load, but such spas may be hard to tune the background bromine level in between soaks unless you can control the on-time of the ozonator or try to be careful in controlling the concentration of your bromide bank.

[Tom Kirshbaum]

Thanks, Chem Geek. Your answers are as crystal clear and the best water! Now, after repeated oxidizing or shocking, when does that original bank get exhausted and require some more doses of the powder?

Tom

[waterbear]

You should be good until it's time to drain and refill in about 4 months if you are starting with half an ounce of sodium bromide per 100 gallons when you start the tub (which produces about a 30 ppm level of bromide reserve in the water). If you have ozone then it might only be 3 months since ozone tends to oxidize bromide into non renewable bromate so the bromide reserve will drop a bit faster..

[quarky42]

WaterBear, I want to also thank you for your help in this thread and others. This directly applies to the Spa I'm receiving on Friday. It has an ozone generator, so I'll know that the bromide reserve probably won't last the full 3 months. I did order the Taylor 2106 kit and will have to read the manual very thoroughly.

I chose the Bromide method because, in theory, it should be easier for my wife to manage when I am out of town and when she wants to use the tub and I don't feel like going out there. (She suffers from nerve pain and I suffer from moderate to severe seasonal allergies...so the tub is for her. I like my air filtered thank you.