How long is the shelf life of activated cactus juice, kept in the plastic paint containers you recommend, and kept in the fridge? Can i buy one gallon and only activate a smaller portion (say 1 quart plus 1/4 of the activator?)

Activated Cactus Juice has a shelf life of 12 months at room temperature. If kept in the refrigerator, it has been reported to last for 2 years.  The thing about Cactus Juice and shelf life...once the shelf life has been exceeded, it will NOT cure or go hard.  It just gets to where it will not cure properly or at all.  If that happens, contact me and I can send me activator if you have enough to deal with and you can rejuvenate it.  I DO NOT recommend trying to activate less than the entire container you purchase.  The activator is a semi paste by weight and needs to be fairly precise (within a gram or two).  You would have to precisely weigh it to get the proper ratio and even then, you can run into issues.  My policy is that I have a 12 month shelf life guarantee from the date it ships.  If you try to activate only a portion, you are on your own and I will not cover it under any kind of warranty.