If you already have a skimmer why not carbon dose to bring down the nitrates? I have a 29, no sump, no skimmer, no algae, no other mechanical/chemical nutrient removal. I feed extremely heavy (2g rods, 1ml reef roids, 1ml coral frenzy daily). Keeping a tank with no sump or skimmer is actually very simple... If the tank was designed in a way where you don't need them. I have a 4" sand bed, and plenty of live rock. With the 29 I feed so much because its nutrient deficient. I actually have another tank (40 breeder barebottom) that has a fairly large amount of fish (7"+). This tank does have a sump, skimmer and a fuge with macro algae. As for right now the skimmer is draining back into the sump, and I still have undetectable nitrate. The common denominator between the two is the live rock I have used.