Teslin, They do treat 1 qt. and i forgot to replace the 1 qt ziplok bag I had in there! Thank god you reminded me or i coulda been in big trouble. Another question i have is, How do you guys treat your water? The MP1 says for 4 hours in a dark place. Where is a dark place? Thanks! Has anyone seen canoedogs, or am i just on too early? I want him to post his PSK! And Everyone Else Too!!!