i dont have a sump on mine and i run a 265 gal reef. i have an aquamedic 2500 hang on skimmer, an aquaclear 110 filter with charcoal, phosguard and a sponge to clean water, heaters and 4 sicce stream pump #7[2500 gal] for circulation. lights are 5 teszla leds. i also have a hang on refugium. my tank is doing great. corals are growing and fish are all fat. i have a mixed asortment of soft and hard corals. i dont have room to put a sump under my tank and it sits in my living room so it not going beside. i also have a ro unit and make my own water so yes you can have a real nice tank without having a sump