Milk kefir vs water kefir

Do these two offer different benefits?

If you are unable to obtain organic milk would it be better to use the water kefir?

Can you interchange the kefir grains, to make milk kefir from the grains used to make water kefir and vice versa?

I have 9 in my family, making enough milk kefir for everyone may be too much for me (financially), at least for daily consumption. Perhaps some days water kefir, some days milk kefir?


TIA,

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