I'm in the process of setting up a new tank for an octopus and I was considering putting in some colored glass jars or vases both for hiding places and decoration. Does anyone know if the additives used to color the glass are safe? Also, what other things are good to use or avoid? I know that food grade PVC is OK, and I've heard of some plastics like leggos or cat toy balls (minus the bell of course). What about resin sculptures?