So I decided to play around and dumped 2 littleneck clams in my QT. They opened right up and they sure are ugly. After a week there, I decided they would go into the display as an experiment. They burrowed into the sand and I haven't seen them since. Anyway, I know these guys are really temperate water clams so they probably won't last long (figure the starfish will eat them eventually anyway). What's another good "supermarket" clam I could use as a cleaner? Looking for something under $1/piece (Littlenecks were on sale for 37 cents that week).