I let my tub go for a week and now my bromine is at zero, the water is dull and it's foaming like crazy. The pucks in the floater were stuck at the top, and not releasing the chemicals. I've seen Nitro's decontamination procedure but it is for chlorine. So far I've shocked it with MPS and added some bromine granules. I'm ready to refill it soon, but it could be a week or so. What do I do?

Thanks,
Michy

You still decontaminate using chlorine even though you will be later using bromine as your primary source of sanitation. After you've shocked with a very high level of chlorine, you will dump that water, refill, and then start your chlorine regimen. If you do the shock test with chlorine at the end (to 10 ppm), you can still then start using bromine since the chlorine will simply activate any bromide salts to bromine.

Thanks Chem Geek. That makes sense.

Could I also just shock the **** out of it with MPS to kill any bugs? Or do I need to do the bleach method?

Michy

Unless you are using Nature2 with its silver ions, MPS alone won't be enough for decontamination. The usual procedure is to use chlorine, and bleach is most convenient and less expensive.

Was the spa showing signs of bioslime (bacterial) contamination prior to the one week of neglect?

No, I don't think so. I haven't actually been in the tub, since it's neglect, so i wasn't able to feel for slime. Unless it's something you can see. The water is just really dull (the best way to put it) and it's foaming like crazy, which I could blame on the pH because it was really high. I've since adjusted it.

Thanks for all your input.

Thanks for taking the time to write all of that up.
I'm using a sodium boromide salt and I don't know my calcium level as I have nothing to measure it with. They did not measure at the shop when I took my water in for a reading.
I'm going to get a better test kit as I've read all over the forums that the test strips are not accurate which I've already noticed. I'll follow your guidelines to a T and post results in a few days.

A couple more questions just for clarity if you don't mind...

1. I was told to add 1 cap full of shock once a week (or 1/2 twice a week). Is this really all I need with the setup I have or should I be adding a little after each soak?
2. I have all this Aqua Finesse that came with the spa, is there any harm in using it with your reccomendations until it's gone. Aqua Finesse reccomends 280mL per week with my 1400L tub. The dealer told me 190mL per week should be fine.

I have never purchased nor used mps and don't have a spa.

That said, I have learned about it from posts at this website but am a little confused with my limited knowledge. I was under the impression that MPS could be used to decontaminate a pool/spa but then something (preferably chlorine) would need to be introduced to keep a killing residual in the pool for sanitation.

While it makes probably little economic sense, MPS could be used for the initial "sterilization" but then a residual would need to be introduced to keep the water sanitized. Is that incorrect?

Richard describes MPS in this post, and the referenced Dupont link. If you look through the various literature and product labeling you'll notice it doesn't say "sanitize" anywhere. It's marketed strictly as an oxidizer. The "non-chlorine" routines use it in conjunction with copper-silver systems such as Nature2, in which case the silver is doing the sanitizing.

So in terms of sterilization, if you're worried about bacteria growth (in a tub that's been sitting drained all summer, for instance) then you need to use chlorine/bromine. If you're worried about excess tannins, ammonia or other oxidizables that would distract chlorine from doing it's job as a sanitizer then MPS does well. It can be used to clear out white mold in lines too, but peroxide does a better job and you usually want to drain the tub once you've cleared the mold out anyway.

MPS by itself is not a sanitizer so should not be used for a decontamination treatment. Chlorine should be used instead. Though MPS is normally an oxidizer, it is considered a disinfectant in one very specific situation -- when used in conjunction with silver ions in a hot (100-104F) tub. Specifically, Nature2 used in conjunction with MPS per directions (i.e. with MPS maintained at fairly high levels) is an EPA approved disinfectant for hot tubs. It is not approved for this use in pools as they are at lower temperatures.