Thanks, Mazza. Good of you to let me know your thoughts. You are right, some do come with a kind of "water-effect" resin but the ones in the TSV didn't. The stems look to be all plastic so I suppose I could try about 1cm in the bottom of one vase to see what effect it has, if any, and if the worse comes to the worst, I could cut the bottom bit off that stem as they are quite long! Thanks again.