Linckia sp stars and relatives can not be spot fed, and require loads of healthy mature LR. A minimum of 100lbs in a 75g tank, 6 months old, with pristine water quality is my minimum for this species. It does not necessarily feed on 'algae' and certainly not nuisance algaes. More likely it feeds on bacterial/algal films, encrusting animals like sponges and bryozoans, and/or the micrograzers found on them. In addition, they suffer from acclimation stress quite commonly, if they did not get a 4+hour acclimation. Can be a tough critter to keep, though the orange is a bit tougher than others. And, if this is a typical size tank (meaning not over 150g), be content with only keeping that star....competition from similar stars is usually fatal for both.