You can use milk kefir grains and turn them into water kefir grains but then they can never be used for milk kefir again. But you cannot use water kefir grain
for milk. Have you seen the site called Yemoos. Its a great learning site. Also, if you go to oneradionetworkcom they have interviews w the Kefir
lady and Amanda Love who talks about making coconut milk kefir. This was very informative for me. Just FYI you can make coconut milk kefir w milk kefir grains but you must always put the milk kefir grains back into milk. I go 2 days making coconut milk kefir then put the grains back into the milk.
If you go on utube they have many videos on how to make milk kefir etc etc. This is the link for Yemoos.