"The EPA has conservative treatment criteria published for chlorine dioxide, as it is used by municipal water treatment facilities.
It is linear, concentration (ppm) x time (min) for treatment. The published date is in CT tables (conc-time)
For instance, you could have 1 ppm for 40 minutes, that is the same as 4 ppm for 10 minutes.
By my recollection, AM should make a concentration that will deactivate giardia 1000 fold in only a couple of minutes."
Keep in mind that anything corrosive enough to kill viruses, bacteria,and giardia, can also make you sick if you get too much of it.
The EPA sets the requirement for water purification. AM needs to use enough ClO2 to do the job without becoming toxic to people. So you cannot just add more CLO2 to shorten the treatment time. After the two chemicals react you have a solution of part A residue, part B residue, and CLO2. The residue and CLO2 determine how toxic the chemicals are. The time required to treat water is set by the maximum amount that can be safely used without becoming toxic. AM cannot simply increase the dose to shorten the treatment time.
Katadyn has a different chemistry which allows a 30 minute treatment to kill Giardia but requires 4 hours for Cycsts without becoming toxic. Bot AM and Katadyn both uses CLO2 and both are register by the EPA. So both are effective against Viruses, bacteria,Giardia, and Cysts. if you follow the directions correctly you will get clean safe water. But since the two products us different chemistry to generate the CLO2 the time required to do the job is different.
Personally I found I was not always waiting long enough before drinking the water. Never got sick but I don't want to take chances. So now I am using a Sawyer in line filter on my bladder. The filter is instantly effective against Bacteria, Giardia, and Cysts and anything larger, but not viruses. So I also add Katadyn CLO2 tablets to my bladder to quickly kill any bad viruses. It works fast enough on viruses and combined with the filter gives me clean safe water with a minimal wait.