Is that 75lbs lr/starfish for a small one, or a large 6 or 7 incher that you see from time to time? I figure if it is small, then you wouldn't need so much rock...but they do grow...eventually. And by "grazing" do you mean that they are strictly herbiverous (sp?) or grazing on the micro and macroinvertebrates within the system along with the algaes? Just asking because to me the lifeforms are all the critters, algae and bacteria that cover good lr. Just wondering if you had one, and have you ever seen it eat anything that you can describe. I know that nobody really knows what they eat...just posing some possible MS thesis questions on the biology of tropical stars.