do you plan to have a high bioload IE a lot of fish? or mostly coral. the SCA-301 will work great in your system with a low to moderate bioload. but you're probably going to want to add 20-30 more pounds of rock. that's your main filter. the key to a healthy tank is enough surface area for the bacteria to grow (porous rock) and enough flow to help the bacteria feed. chances are 50 pounds of rock is not enough unless youre going with a very low bioload tank.