When I had a clean slate 15 years ago before I put very many things in my greenhouse, I decided to build a still pond and a stream. The water in winter helps to increase humidity levels, and well it just looks cool. This was the beginnings of the stream, years ago, and what it looks like today. I 'stream scaped' the thing with plants from aquarium stores (anubias, different varieties of Spathophyllum, anthuriums, dracaena that I bought in those little boxes at Petco where they let them dry out and almost die before giving them away for 25 cents each...and some thinks have just fallen in and rooted and are happily growing, like some epiphytic cacti, Hoya obovata, dieffenbachia, costs ginger (yes it will grow in water) and syngoniums.