Chemhead

The two of us for about 45 minutes on average and the temp of the water is 100F. Ya I have the floater adjusted to more or less a random setting. I haven't gotten a chance to figure out the proper height to set it at. No I do not believe that I have an ozonator. It's a Great Lakes, 5 person, round, 309 gallon spa.

Yes that is the shock that I am using. I realize it's a non-Chloro shock but it is what I have. I plan on switching to bleach when I run out. So as far as a Br- bank, when I filled my spa back in August it was before I came across this forum. Before then I was just going with what the local dealer told me (through in the tablets and you'll be fine) so I did not add in sodium bromide. I have been adding tablets since I changed the water ( about 2 a week) so should have a Br- bank of sorts yes? So there is 2 of us that use it about twice a week and throw some shock in each time right after. I guess I could need to put more in when I do but at what rate does the ppm of bromine go down on a closed tub that has not been used for several days because like I said ealyer I have been checking almost daily, adding shock after each time I check, and nobody had been in it in days and I still see low Br-.

Are you referring to SpaPure Spa Oxidizing Shock? That is non-chlorine shock. If you did not initially set up a bromide bank (i.e. add sodium bromide) or have not been using bromine tabs, then there is no bromine being created in your spa. The non-chlorine shock has no bromide to react with to make bromine. The proper way to use bromine is to initially add sodium bromide, usually at a dose of 1/2 ounce per 100 gallons, after which you can use either chlorine or non-chlorine shock to oxidize the bromide to bromine.It's also possible that you simply aren't adding enough to handle a higher bather load. A bromine level of 5 ppm in 350 gallons would only handle around 20 person-minutes of soaking. You should add more oxidizer if you are soaking more. The general rule is to add whatever amount you need so that you still measure a residual for your next soak and that it never gets to zero (or close to zero) in between soaks.

So I have a question about keep Br- stable. For the last week I have been checking almost daily and every time do there is virtually no free Br-. So when I see that I add three cap fulls of shock (spa pure oxidizing shock) and get the level up to ~5ppm but after a day or so there is none left. My pH is about 7.6, hardness 280ppm and TA 60ppm tonight when I checked. Any suggestions or great wisdom?