algae on zoa

Hi fellow members, New to the reefing world and still learning. I have a 20 G tank with good parameters. Tank is under 8 weeks old. I have 3 questions regarding 1) green looking algae in my filter 2) on my coral and now at the base of that corals plug (coral I am not sure what it is; I won...

My dau gave me a frag of zoas for xmas. It has 2 types of algae on it, and one polyp has a purplish coating on it. How do I get rid of the algae. I've read some posts on the internet about dipping in peroxide. don't want the stuff to spread into my tank. For CUC I have 3 cerith and 2 turbans. No...