I know it jump starts algae growth but what happens if you don't have the algae to begin with or don't know if you have it? Will adding purple up or coralline algae work? I started my tank 6 months ago and all I have are 2 clown fish and dry rock, which I added a week or two ago. Im not sure if I even have the algae so should I invest in this stuff. I can't go outside to get some purple rock either.