Ive been thinking about getting one for a long time for my 20 but ive never pulled the trigger because some people say its worthless in small systems. Im not looking for a escape from weekly water changes, i understand the need for weekly changes and how important they are in nanos but wouldnt having a skimmer on inbetween those weekly changes help, especially if i feed my corals/fish heavily? I barely have sps so im not trying to keep the cleanest tank but i figured it could be benficial to run one. Ive read on several forums saying that a skimmer cannot funtion "properly" due to the low volume of water. Pretty much just looking for someone to explain and help me decide if i should get one or not.