from what I read on the RCIA site if you add iso to your mix it will attack moss better than with out it. my question is if I use iso in my mix how long will that mix be good for? and do I need to add iso to kill the moss on roofs? or is just sh, water and ammonyx lo good enough?
By ISO, I assume you are referring to IPA. Isopropyl Alcohol. If so, then follow the same guidelines for adding IPA that you would for any other additives, in regards to the longevity of your mix.
The IPA is not chlorine stable like the ammonyx is. Just like dawn, as soon as you put the IPA in your mix it will start to degrade your SH. Only mix what you plan to use within 48 hours.