Get a protein skimmer. Ornatapinnis sums up its function very well. Protein skimmer pull out fats, lipids, and other organics out of the system before your bacteria have a chance to break it down into nitrates. So in a nut shell,... not as much fish waste,...not as much nitrates,...not as much water changes....get a protein skimmer. CPR makes a good HOB skimmer for up to 65 gal. simple and not much to break. Red Sea's prizm is a very slim HOB skimmer that work up to 100 gal. If this is a 250 to 300 gal their berlin turbo HOB works very well. Ive used them all in many different tanks that didn't have a sump. Just remember...Big Fish ....Big S___. As much live rock and as big a skimmer as you can get.