Sun tea uses tap water and is brewed with the sun's rays. It doesn't have to be sweetened, but I find some agave nectar makes it a bit more pleasant to the pallette - though even with a generous dollop, it's incredibly healthier than the average store bought sweetened iced tea. If made correctly and consumed quickly there's no health risk despite what some internet articles might claim. I've started making large batches of it on the window sill in reused bottles that have been through a dishwashing cycle. Every bottle of sun tea consumed means one less new bottle bought and used. So far I've saved more than 200 new bottles from being bought/used/recycled - and that number goes up by about 25 every week. Lately the bottles have been disappearing faster, and I get a new compliment or 'thankyou' from a co-worker every other day, making it rewarding on many levels.