You definatly DON'T want these in your tank.They will very quickly cover the whole tank.The best way to get rid of them is to put the infected rock in a bucket of saltwater,and carfully remove the bubbles.Then rinse the rock in another bucket of salt water.Then dump that infected water out,and start over wth the next rock...Some will tell you to get emrald crabs.They do eat the bubbles,but in the process they also release thousands of spores that spread throughout your tank.Two or three crabs may be able to keep up,but that is really only treating the symptoms,not curing the disease...