Moss and Algae (and liverwort) will grow well on damp tufa rock here- which I believe is very alkaline ... Peter (UK) On Thu, Feb 2, 2012 at 4:04 AM, Ken <kjblack@pacbell.net> wrote:--- On Wed, 2/1/12, Fred Biasella <arlen.jose@verizon.net> wrote: I water my plants with rainwater only, which is rather acidic inthe Northeast and since algae and mosses love acid conditions,..