for those that dont understand how this works. you pressurize the tan,k hock up to a water tap and start working. it makes pure water on the go no storage needed. you could leave this in your van and just hock up to water with one hosed and have a second for working with.
one tank of air should last a few hours. in the photo you can see a black cap on top of the tank this is where you fill the air. the resin should last about a month so that will cost you half a bag each month at about £60 a bag.
i put in a tds metre as well