I have a bright orange sea sponge that sort of looks like a cactus. It is 6 inches tall, has about 5 or 6 branches, and the edges look sort of spikey. It had some algae growing on it which i brushed off with a small watercolor paintbrush, but now all of the edges are turning a pale tan color. I have it placed with moderate flow, midway in tank at one end. My lighting is T5 high output flourescent, total of 1.5 watts, and i have one actinic blue light. My tank is 80 gals. My question is how do I tell if my sponge is alive, and how do I care for it. I cannot find any information on the internet regarding care, health, feeding, etc. Suggestions would be helpful, and website referrals welcomed.