i used kalkwasser mixed with enough water to make a paste took a syrenge and shot it in the mouth it dissolves them from the inside out. they are aggressive eaters but if you miss they may retreat inside the rock but this is the best way i found to get rid of them. do not cut or scrape it off the rock even the slightest piece of one left behind can creat a new one or several new ones _________ karla  75 gall, 80 lbs sand, 110 lb lr, 10k pcs, atinics, emperor 400, prizm skimmer, hagen and maxi jet powerheads |