A protein skimmer is one of the most distinctive pieces of saltwater aquarium equipment, removing dissolved organic waste before it ever has a chance to break down into nitrate and phosphate.
How Skimmers Work
Skimmers use a column of fine air bubbles to attract dissolved organic compounds, which collect as foam and are pushed up into a removable collection cup for easy disposal.
Sizing a Skimmer
Choose a skimmer rated for a larger tank than your actual volume, since manufacturer ratings often assume lighter stocking than most hobbyists actually keep.
In-Sump vs. Hang-on-Back
In-sump skimmers are generally more efficient and are the standard choice for tanks with a sump, while hang-on-back skimmers work well for tanks without one.
Do Freshwater Tanks Need Skimmers?
No — protein skimming relies on the physical properties of saltwater and isn’t effective or necessary in freshwater setups.
Browse skimmers and other equipment in our aquarium accessories category.

