I just bought a small castle to put in my aquarium. I like the colors and the effect it has on my aquarium but I wish it had more holes in it for fish to swim through. I would like to drill holes in it, specifically where the doors on, and drill to the back of the castle. I think there is no problem with the structural integrity of the castle but if I do this, will I need to treat the newly exposed innards of the castle? The ornament feels very hard, as though it were made of some kind of pottery, but I am not sure.
