Gravity feed diy di vessel using a co'op 2 litre cola bottle, some hard foam, a lint free rag and some sponge. It has 1 litre of resin in it and 4 months later after putting a fair bit (1000's of litres) of rainwater through it the ppm is still at zero and I'm still using it. I will get around to building a better looking one from drainpipe or similar but for now until ppm goes up I'm fine with this thankyou.

