False ocellaris? Sometimes ocellaris are referred to as false perculas. I would suggest you get Joyce Wilkerson's book, Clownfishes. It is a very good reference for keeping any type of clownfish. To answer your questions, if you only plan to keep ocellaris, you could get by without a protein skimmer and just do small, weekly water changes and have a power filter with activated carbon in it to absorb organic wastes, and change this every week to 10 days. Ideally, you would start off with a 15 or 20 gallon tank. You would have a small protein skimmer also, as these keep the water quality higher. You definitely will not need to add any other type of animals or corals in such a small tank. You need lots of experience to successfully keep fish in corals in such a small tank.