I have ramshorn snails in my divided betta/ shrimp tank and they die. Especially in the shrimp side. I have moved some of them to planted jars in the windows and in just a few weeks they are 3 times the size whereas the ones in the aquarium just aren’t thriving. There are still plenty, but they grow so slowly and the ground is littered with dozens of empty shells. It don’t feed the snails specifically, the shrimp and betta get pellets/ freeze dried food every couple of days. I have hard water so they shouldn’t be dissolving. Does anyone know what could cause this?