Fluval A402 Aquarium Air Pump

The Fluval A402 is a 4.0W air pump for running air stones, sponge filters and other air-driven devices. Bubbles rising through the water stir the surface, which lets oxygen in and carbon dioxide out. That helps fish, plants, corals and the bacteria in your filter.

Independent outlet control

Each outlet has its own control dial, so you can set them separately. Run a strong stream to an air stone on one side and a gentler flow to a sponge filter on the other, without adding external valves. That’s handy in a tank with more than one air-powered device, or when you split one pump between two small tanks.

Built to stay quiet

Air pumps are often the loudest thing in the room. Fluval fitted this one with a baffle chamber that damps noise and oversized rubber feet that cut vibration against the shelf. Setting it on a soft mat and keeping the tubing from touching the stand helps further.

What you can run

• One or several air stones for extra aeration
• Sponge filters, such as the hygger double sponge filter
• Bubble ornaments and other air-driven decor

Fluval notes a good ratio of output flow to pressure, which matters when airline runs are long or air stones sit near the bottom of a tall tank.

Setup tips

Place the pump above the waterline, or fit a check valve in each line, so water can’t siphon back into it during a power cut. Replace air stones when the bubbles turn coarse, since a clogged stone makes the pump work harder.

Who should look elsewhere

If you only need a single small stream for a nano tank, a smaller one-outlet pump like the hygger quiet mini pump is enough. Fluval offers a two-year limited warranty on the A402.