I got the tufa rock at an lfs here in town.i dont know about that syno man, i would def get a bigger multi maybe even an adult he may make them a KFC snacker, you know what i would do a lelupi you may have a fight or two but with those rocks, which BTW were did you get those at, would provide a retreat for whoever is going to get punked, if you do go with the shellies i would add about 4 shells per fish ratio..