hi - this is Steve.
You may wish to read this web page.. I have not had any direct experience with "Water Kefir" - although I have used Milk Kefir (ordered through G.E.M. Cultures) in the USA.
I must say, it sounds good.
Anyhow, here's that site.http://www.weim.net/homeovet/Docs/water%20kefir.pdf
Peace and love,