I have recently noticed my turtle scavenging for food in his tank more and more often, sometimes biting leaves (they're fake), biting green spots on the floating dock and always poking his head through the gravel. I am in the process of trying to get my hands on some river sand and turtle grit to replace the gravel but I am still really worried he might accidentally eat the rocks. Also, when I take him out of the tank to feed him in a separate container, he sometimes tries to snap at my fingers and once I saw him snap at his own legs. I feed my turtle once a day, about the size of his head (as recommended), but he still always seems so hungry? I thought it might be the water temperature but my water heater is on the lowest setting and the water temperature reads about 24-25. Should I be feeding him more? Currently I've been feeding him frozen baby turtle food blocks but I'm trying to find a good aquarium near my area (I'm in northern suburbs of Melbourne if anyone has recommendations) that can provide some good advice and products to replace them. Also, I've noticed a white spot on his shell which looks a bit like it's chipped or something and I am worried it might be something serious. I've run out of turtle conditioning blocks and am trying to find some new ones. Any advice would be great!