>3. Mix it with the bottom 1/3 of your 1-3mm non-calcium carbonate bearing >gravel >4. Cap with 1/3 well washed PLAIN non-calcium carbonate bearing gravel >(total depth at least 3") > >Karen Randall >Aquatic Gardeners Association > Er...Karen,what about the remaining 1/3?? :-o Ouch! Ok,u don't have to hit so hard!! :-P Khew