hi, i recently learned about water beads (they are some type of polymer used (not sure what it's made out of) that a lot of gardners use to keep their plants watered since it's retains water well and releases water is small doses. another use is in vases for flowers... but i wonder if they are safe to use in a fish tank. I presume not, but they are so pretty and just thought i would ask if anyone has any experience.