I have a 16 gallon biocube with some snails that don't eat a lot of algae, zoanthids and a blastomussa coral, and a citron goby. My question is, I have a lot of algae growth on my sand bed and it looks like I am getting some hair algae on my rocks. I just got the corals yesterday. If I were to add a tuxedo urchin today, would that stress anything out? I also have some nori if it runs out if food.