This guy has an awesome little aquarium. I can't believe it's only 10 gallons. I don't know very much about saltwater aquariums, but I was wondering how do you get purple algae? Is it the lighting? Do you have to buy live rock that already has it on it? I'm wondering... if you do have to buy it special, if you get just a couple of pounds of live rock with purple on it, will it spread to the rest of the live rock? Let me know what you guys think. Thanks.