Water to get the chlorine out. Filtering water for the garden seems to be rare here and not everyone has a waterbutt which is also weird. The carbon filters aimed at the garden market are carbon encased in plastic. They work but you end up overpaying for the carbon and having to throw the plastic casing away every 6 months and then there is potential leaching from sun exposure. Ever drank water from a sun exposed hose on hot day...yeah not good.
Also there is micro plastic everywhere so even though its only a small amount I don't really want to unnecessarily contribute to more of it. So I have been working on throwing together a stainless steel one it seems to working pretty well overall at the moment.
