I'm using the fish tank filter stuff, it was just a large rectangle sold loose, and I make a little cap with tea bag material after reading about it somewhere else on the forum, and then I put a little plastic piping down the side of the cart, the pipe is polyurethane I think, used for a pneumatic paintball gun. The carts working well like this, fills up fine and smokes until quite dry, and no burnt plastic taste from the polyester fibres. It leaks quite a lot if carried around while vaping, but I think that this is an inherent problem with 801's anyway, just got to carry it around dry and stop and fill when I want a vape.