I have had a marine tank for about 2 years now. Its a 20 gallon tank with no live rock and only 1 clown fish, 1 emerald crab and a few snails. I have never had a skimmer and haven't really had any problems. I have a heater and a Penguin Bio Wheel filter. After reading a few things on this site I have decided that a skimmer is the way to go.
I'm going to be adding live rock to the tank soon. What would you suggest for a 20 gallon tank? Running the skimmer along with the live rock is all I need for adequate filtration? What about power heads?