The active ingredient is potassium peroxymonosulfate. That is in the sanitizer product. What do you think?
We have had this spa for 3 years and it always appears clean and clear. Now I am a little worried.
Ruth

MPS is a "non-chlorine shock" Richard referenced.

Potassium peroxymonosulfate is what we call MPS, and is alright in a spa if used correctly.

would it be better to switch to the bbb method or keep using the non chlorine products?

If you have a system for taking care of the spa that you are familiar with and you haven't been having any problems, I would stick with it.

Thanks, Jason.
I just put the Pool Calculator on my iphone and I love it!!
But, I can not figure out how to set up my target goal.
I put the target on 6.0 and it still shows that Goal: Not Setup.
Can you help with that?
Ruth

Scroll the list of tabs across the bottom to the left till you see the Goal tab. Clicking on Goal will take you to a page where you can answer the questions to setup your goal levels.

Thanks so much! Makes me feel stupid when it is so simple!!
You are the best!

Just so you know, if you are using MPS without any silver ions, say from Nature2, then this isn't technically sanitary. The EPA only gave approval for MPS when used in conjunction with Nature2. In practice, at hot spa temps, MPS even by itself is pretty good, but it's not as good as chlorine or bromine (or MPS with silver ion). Also, without the silver ion, a minor component in MPS can be irritating (with silver ion, that minor component breaks down quickly).

Richard,
There is a " Vision System that contains a silver catalyst bed with a large surface area. As water passes through the Vision System, the silver combines with water where it then serves as a residual bactericide." Is that the same as the silver ions?
Ruth

Sounds like it is a "mineral system" (silver ionizer)...

Yup, that sounds good.