If you are trying to keep them alive and not use dairy, I've had milk-kefir grains fermenting water-based stuff at the office for over 9 months. They were happy to ferment fruit juice or water+sugar or water+sugar+fruit (I mixed it up depending on what is left over from meetings). I made a video of the grain at about 6 months.
https://www.youtube.com/watch?v=4EneTUFd-r0About a month ago, after doing lots of reading, I learned that the bacteria that grow the grains can only make the grain from glucose and galactose, where fermenting milk lactose is converted to galactose. But there are other sources of galactose, e.g. honey has between 1.5 and 3%. So I've been feeding my grain on honey water (rather than sugar water) and I believe its growing. Not fast but then the grain had 8 months of non-growth so may take a while for lactobacillus kefiran to multiply to the point of making it grow.