Bromine and chlorine

[blowupspaguy]

I have been using chlorine for a while and have recently switched to bromine.  After reading up a bit about the bromine switch i realized that i did not need to drain my spa in order to switch.  I used a bromine booster at first to bring the bromine base up to 30ppm and after testing i did not see any results.  I then added the suggested bromine floater tablets (2 for my 210 gallon spa).  And still have not been able to get a reading of over .5 ppm.  Since, i have added chlorine into the floater and have still not seen a good reading.  Do i have bad test strips or am i doing something wrong?

[Kev B]

Add Sodium Bromide (A type of salt) to the water only on start up, it does not evaporate. Then I shock with Potassium Monopersulfate (Non-chlorine shock) once a week or more if needed. The shock activates the bromine.

[Dr. Spa™ Ret.]

What exactly is this "bromine booster"? Likely, it's mostly chlorine. As Kev B says, you need to initially add sodium bromide...and there's no way to test for this. Sodium bromide is then converted into bromine when oxidized (by Potassium Monopersulfate, or chlorine, or to an extent by ozone)