so i was at dinner and in the parking area i saw a million of the most beautiful rainbow rocks about baseball size and very bright....spoke to the manager and he said take whatever u need-----before entering them into my aquarium i need to know first after sterilizing them by boiling and rinsing them would they harm my fish---secondly i'd be using egg crates but if i filled the entire bottom of my tank with these rocks would that be too much wieght for my 240gal to support
