The pros and cons (and myths & legends) of plastic vs. glass were debated at length a little while back, to a dizzying degree of technical detail on permeability rates etc etc etc :blink: - not exactly on point if you are only planning to ferment in plastic but well worth a look anyway-
BB, you thought the debate about plastic versus glass was bad....
Quite a bit or research has been done on gas permeability of high density polyethylene (HDPE) containers versus polycarbonate (PC) plastic too. :unsure:
The spring water containers Chiefman is querying are made from PC... PC has about twice the gas permeability for both oxygen and carbon dioxide. This can be perfect for the lambic brewer but no so for your standard secondary ferment.....