Simplicity DC In-Sump Protein Skimmer

The Simplicity DC In-Sump Protein Skimmer pulls dissolved organic waste out of your saltwater aquarium before it breaks down into nitrate and phosphate, for cleaner water and healthier corals. Every model was designed and tested by reef hobbyists to deliver the performance of far more expensive skimmers at an honest price. Five sizes cover everything from nano reefs to 800 gallon systems. Explore more of our reef and saltwater gear.

How It Works

The DC pump's needle-wheel impeller shreds incoming air into a cloud of fine bubbles that bind to proteins and organic waste. As that bubble column rises through the hybrid-cone body, the foam concentrates and carries the waste up into the collection cup, where it is removed from your system. Adjusting the air intake and internal water level lets you tune the skimmer for wet or dry skimmate to match your tank.

Features — All Models

Choose Your Size — Model Comparison

Select a model in the tabs below for its full individual spec sheet.

Detailed Model Specifications

Click a model below to view its complete specification sheet.

Which Model Is Right for You?

120DC — Nano and small reefs up to 120 gallons (60 gallons heavily stocked). Compact 4.8 in body for tight sumps.

240DC — Small to mid-size reefs up to 240 gallons. A big jump in air and cup capacity over the 120DC.

320DC — Mid-size reefs up to 320 gallons, the sweet spot for many mixed reef systems.

540DC — Large reefs up to 540 gallons, with an 8 cup collection capacity for long service intervals.

800DC — Very large or heavily fed systems up to 800 gallons. The most air draw and the largest cup in the line.

Choosing by Bioload

Skimmer sizing depends on how heavily your tank is stocked and fed, not just water volume. Use the Heavy Bioload rating for a fish-heavy or heavily fed tank, Medium for a typical mixed reef, and Light for a lightly stocked or LPS/soft-coral system. When in doubt, size up.

FAQ

What does a protein skimmer do?
It removes dissolved organic waste as foam before it decays into nitrate and phosphate, keeping water cleaner and corals healthier.

Is this an in-sump skimmer?
Yes. Each model is designed to run submerged in a sump at the recommended water level listed in its spec sheet.

Is the pump adjustable?
Yes. Every model includes a digital DC controller with adjustable flow and a Feed Mode that pauses the pump for 10 minutes during feeding.

How do I pick the right size?
Match the model to your system volume and bioload using the comparison table and the Light/Medium/Heavy ratings in each spec sheet. Heavily stocked tanks should size up.

Freshwater or saltwater?
Protein skimmers are for saltwater and reef aquariums (they also work in brackish water).