Mine are multiplying very fast! I bought them from http://www.kefirlady.com/
Are you rinsing very well between batches? & not using chlorinated water?
1 qt spring water
1 cup fresh young coconut water
1/3 cup sugar
cover with cloth & rubberband
wait 24 hours and taste, it usually is not sweet after just 24 hours
lots of bubbles throughout the day
I think mine doubled in a week!