Newb with bromine tub (drop chlorine quickly?)

[Brian VT]

I've read the sticky. Searches turn up a wealth of info. but I soon get overwhelmed with chemistry talk.
Maybe I need to get deep into the chemistry but I'm hoping not.
I've got the alkalinty @ 80. I'm using bromine tabs in a floater. No ozonator.
Before bathing, PH and bromine looked good on the test strip.
After bathing (2 people for 1 hour) I put in a cup of Clorox (355 gal. tub) and ran the jets for an hour per the sticky.
The ph and bromine spiked to off the chart.
Is this to be expected and how long before they come down to a level that's safe to bathe in?

I ask this now because I have guests coming tomorrow afternoon and some will want to use the tub and I'm concerned that the chlorine level may still be too high at that time. Should I stick my stinky feet in there now to use up some of the chlorine?

 

[chem geek]

Re: Newb with bromine tub

You may have put in too much bleach. Also, I think you forgot to add a bromide bank by adding sodium bromide (1/2 ounce per 100 gallons) to the tub. Eventually the bromine tabs will add enough bromine to form a bromide bank, but usually you want to add sodium bromide to start one right away.

The rough rule-of-thumb with no ozonator is that every person-hour soaking in a hot (104ºF) spa requires 3-1/2 teaspoons of Dichlor or 3-1/2 fluid ounces of 8.25% bleach or 7 teaspoons of non-chlorine shock (43% MPS), BUT I doubt very much that your spa was 104ºF during your soak since you normally cannot or should not soak for an hour at that temperature.

Also, you should not measure the bromine soon after you add the bleach because it should spike up. The bather load is not immediately oxidized -- this takes hours. You should measure the bromine 24 hours later before your next soak. You want it at around 2-4 ppm bromine before your soak. If it's too high, then add less bleach after your soak. You'll soon figure out the right amount needed.

Also keep in mind you've got your bromine tabs also adding bromine, but usually you want to adjust the feeder to just add enough bromine to maintain a bromine level in between soaks.

If the bromine level is very high and you want to lower it you can use a chlorine/bromine neutralizer (usually sodium thiosulfate).

 

[Brian VT]

Thanks.
Are there any common household products that could be used as a neutralizer?
If not, will running the jets with the cover off bring the chlorine level down?
Will bathing in it "use up" some of the chlorine? (I'd put my feet in for a while)
I'd like to get the chlorine down to a safe level before guests arrive later today.

 

[chem geek]

For chlorine, one can use hydrogen peroxide to neutralize, but I don't think that works well with bromine since the hydrogen peroxide may create more bromine from the bromide bank.

Running the jets with the cover off should outgas some of the bromine. Having bather load would use it up but that's slower if it's just your feet.

What is your bromine level now? I'll bet it's down low enough to be safe to use. Maximum chlorine levels for spas are usually around 5 ppm and that's with no CYA so the equivalent bromine level for that is roughly 10 ppm.