Make your own agua de pipa/coconut water?
So I've realized that I have an affinity for packaged coconut water and it helps me (very physically active) stay hydrated, but it's very expensive. This is compounded by the fact that I used to live in a tropical country where young coconuts were easy to come by, free or 25 cents, in season. I also don't like how many commercial brands of coconut water use environmentally-unfriendly packaging. I can give up drinking this stuff, i suppose, but I wonder if there's any way to make it myself, or if there's some sort of powdered product that I could add to regular water to create the same drink with less waste?