YOU will need a protien skimmer especially with corals! The filter is needed but a good one is not as important as a GOOD protien skimmer. Skimmers are really really good for the system. Filters collect garbage from floating around the tank, skimmers on the other hand remove garbage, IE: fish crap and excess food, and physically remove them from the water. Then all you need to do is wash the bowl every few days or so. You can never over skim. Plan for something larger so that in the event that you upgrade your tank you can move your skimmer over. Once you have it you dont have to buy it again so its a good investment. And if you are at the top end of your rateing of skimmer then move to the next size up.
