Simplicity 120 DC In Sump Protein Skimmer; A high-quality, dependable protein skimmer is essential for reef aquarium health — that's where the Simplicity 120 DC In Sump Protein Skimmer comes in. This efficient protein skimmer removes organic waste to help maintain low nitrate levels with its smart design and custom controllability. Simplicity prides itself on its unmatched value, support and efficiency in aquarium parts and accessories.