No 47 is the size of the membrane and 22 is the thickness.. and u only have to filter once bro.. but each membrane serve dif purposes .. so getting the right one is the most important part in filtering.. and having a machine vacation pump with tht filtration is a must for filtering quick. As the filtration process needs to be filtered as fast as Possiable.. if not then bacteria could set into ur finished ass.. not to mention tht the cooler ur brew comes while filter the chance u could loose hormone In ur membrane leading to loose potency as well as clogging ur membrane.. and this type of filtering dosnt work good for micro brewing fellas... big brews are really only needed for this type of filtration.. however they do have dif sizes of flasks for smaller brews but no worth the investment if ur brewing 100ml and under... hope this helps yall.w
... LAB 67 ...