I use Bromine in my indoor pool

[jenspool]

HI, I'm new to the forum and though I've had my pool for over two years now, I still have a lot to learn and have had to learn by trial and error and a lot of researching online.
I use Bromine in my indoor pool and usually manage to keep it clear and problem free as long as I keep the bromine in the feeder. I don't shock often, but I did last week and must have used too much. I now have very high Bromine and Free Chlorine readings - off the charts. The PH is about 7.2 today but was off the charts high yesterday, the TA is low - about 40. I would like to start using the BBB + Bromine method but don't know how much of the "B's" to use. I tried the calculator but it doesn't work for Bromine - there really isn't a lot of information on using Bromine with pools.

 

[chem geek]

Welcome to TFP!

Because you already have bromide in the pool built up from the bromine tabs you've used over two years, you can probably just reactivate it using an oxidizer and the cheapest effective one is chlorine, so chlorinating liquid or bleach which will convert the bromide to bromine. You can still use The Pool Calculator for calculating this by realizing that your Total Bromine number is just 2.25 times the Free Chlorine number. So if you have a bromine target of, say, 4, then just divide by 2 and use 2 ppm FC in the Pool Calculator to calculate how much chlorine to add.

With an indoor pool, the rate of bromine loss should be slow enough that you only have to add more disinfectant once or twice a week so probably don't need to use the tabs which will also save you further cost. pH and TA and CH adjustment and targets are all the same as when using chlorine.

 

[jenspool]

Thanks chem geek! 23 boxes of baking soda (according to the Pool Calculator) seems a little excessive and I think in this case it would be cheaper to use alka boost... but it is great to know that I can cut out the bromine tabs and just use bleach. Right now it looks like I need sodium thiosulfate to bring the FC level down.

 

[chem geek]

I don't think you need to raise the TA by very much. You have a vinyl pool so don't need a higher TA or CH. With the TA at 80 ppm, your pH may rise more, though with your pool covered most of the time it might not. If I were you, I'd raise it just to 60 or 70 ppm and see how that goes. As for what to use, baking soda is only a lot cheaper if you get it in the larger volumes, but you can just compare prices directly per pound and if Alkalinity Up is less then that's fine.

Unless your bromine level is really high, say 8 ppm or more, I would just let it drop on its own after taking out the tabs. There may be some moderation of bromine's strength from the DMH leftover from using the tabs, but we don't know by how much and it doesn't seem to be as much as CYA moderating chlorine strength.

Is there any particular reason you went with bromine rather than chlorine?

 

[jenspool]

The bromine level and FC levels are very high - at least 10 ppm and not going down - the pool hasn't been in use and there isn't enough sun.
The bromine was in use when I bought the house and pool - I guess the previous owners used it because it's an indoor, heated pool and the hot tub also uses bromine.

 

[chem geek]

OK then. Yes, you can use a reducing agent to lower the bromine level. The same ones used to lower chlorine levels will lower bromine levels as well.