Potassium Monopersulfate shock

[waterbear]

I realize that you are trying to have a discussion. I can also tell you this from my own experiences. I used to have a large portable spa that I ran on bromine for several years. I had all sorts of problems when I used MPS for shocking (algae blooms and cloudy water) and they stopped when I started shocking with bleach (don't know for sure but I think the bleach is more effecient at reactivating the bromine bank).
I also work in a pool store. I test water all day and tell people what to put into their pools. I recently had several customers that were having problems with cloudy water and algae that were using MPS. (It generates more revenue for the store and is recommended often by some of the employees) I suggested they try sodium hypochlorite or cal hypo for shocking and EVERY ONE OF THEM came back and told me that the problems stopped when they switched and have not returned so far. I know that is not proof but it is in line with my personal experience also.

There is has also been some discussion that I have seen on DuPont Oxone (this is what mps shock is) that it might not be safe to swim right after application. the jury seems to be out on this one yet.

Also, right on the DuPont website
http://www.dupont.com/oxone/index.html
they state that it needs to be used as a preventive maintenance before chloramine form and that is will oxidize only nonmicrobial contaminents, they state that it will not effectively reduce chloramines (breakpoint chlorination is required for that), and that it is not as an effective oxidizer as chlorine.
They aslo state that it can lower pH and TA!

It also introduces sulfites and sulfates into the water and there has been some discussion on this forum in the past on how these can have adverse effects on plaster pools.

IMHO, MPS is a good choice for an indoor pool to help eliminate some of the problems that occur but for an outdoor pool it really has no benifits.