yea, it really does become a plague, i didnt know what they were at first either, by the time i found out my tank was infested, but at least i didnt have any other corals or anything in it at the time, my solution was the powder you buy from the store, mix it with a bit of water and feed it to them, it works =) but if you do want to save some money i guess soaking the rock in fresh water could work, but i think it would be harmfull to the live rock and it can kill off the critters that live in the rock.