Having just parted with £240 for a new Nature pure drinking water kit for the van and informed that the new filters last longer but are £50 a go, I was thinking about extending the life of said filters as much as possible. Was thinking about one of the inline filters they use in caravans with hose locks and attach it to the filler pipe when filling the tanks. Does anyone already do this, and how much does it slow down the water flow when filling the tank. A sort of pre filter to extend the life of the Nature pure filter, if you understand what am saying. Before anyone states that £240 will buy a lot of bottled water. I know that, but I dont have to carry the stuff from the supermarket, and then find somewhere to store 10 litre bottles.