I was using a double thickness of cheesecloth but I found too many little threads floating in the water so they've come out temporarily until I can get something with a tighter weave that won't fray as easy as these did. The one in the pot standing upright is still in there but it's all covered with rocks so nothing is getting loose from it. The ones in the pots laying sideways were the ones that seemed to be letting loose and it wouldn't have been long before the flourite was loose in there.

todley