Protein Skimmers 101 — Do You Need One?

If you’re setting up a saltwater or reef aquarium, protein skimmers come up in almost every equipment discussion. But what do they actually do, and do you really need one? Here’s a straightforward breakdown.

What Is a Protein Skimmer?

A protein skimmer (also called a foam fractionator) removes dissolved organic compounds (DOCs) from the water before they break down into ammonia. It works by injecting fine bubbles into a reaction chamber — organic waste binds to the bubbles and rises into a collection cup as dark, smelly skimmate.

Benefits of Running a Skimmer

• Removes organic waste before it converts to nitrate
• Improves water clarity and oxygen exchange
• Reduces the frequency of water changes needed
• Essential for heavily stocked or high-bioload reef systems
• Especially important when keeping sensitive SPS corals

Do You Need One?

It depends on your system:

• Fish-Only Saltwater: Recommended, especially with heavy feeding or large fish
• FOWLR (Fish Only with Live Rock): Strongly recommended
• Reef Tank: Yes — skimmers are considered essential for most reef builds
• Nano Reef (<30 gallons): Optional if lightly stocked and water changes are frequent
• Freshwater: Not applicable — protein skimming doesn’t work in freshwater

Choosing the Right Skimmer

Size your skimmer for more than your actual tank volume. A skimmer rated for 200 gallons on a 100-gallon system will run more efficiently and handle unexpected bioload spikes.

• In-sump skimmers: best for established systems with a sump
• Hang-on-back (HOB) skimmers: great for smaller or sumpless tanks

Shop Protein Skimmers

We carry quality protein skimmers including Seatorch Skimmer units in our Aquarium Supplies collection. Come in to chat with us about sizing for your system.