I think its the depth of the sand bed thats more important than your square footage. I can say, that after I got my star at the advice of the LFS my tank did go downhill. It could be coincidence but it was then that my algae outbreak took place. I think he probably killed all the filtering power of my sand bed, allowing the nutrient levels to spike. That combined with aging bulbs and I had an outbreak.
He lived for about 7 months before I looked in and he was dead. I don't think he actually starved, as there was no sign of disintegration, but it just wasn't a good situation for him or my tank.