ALEGI Aquarium Bio Sponge Filter Kit (40-80 Gallon)

The ALEGI Bio Sponge Filter Kit is an X-Large air-driven sponge filter for tanks from 40 to 80 gallons. An air pump pushes bubbles up a lift tube, which pulls water through the sponge. The sponge catches debris and grows the bacteria that break down ammonia and nitrite, so you get mechanical and biological filtration from one simple unit.

What comes in the kit

• 1 sponge filter
• 4 feet of air tubing
• 1 check valve to stop backflow
• 2 suction cups
• 1 Y-connector

You only need to add an air pump.

Why keepers use sponge filters

Sponge filters are hard to beat for fry, shrimp, bettas and other fish that struggle with strong currents. The intake is just a sponge, so small fish and shrimp can’t get sucked in. Many keepers also run one next to a main filter as a backup. A seeded sponge can be moved into a new or hospital tank to give it a working biofilter right away.

Setup

Connect the airline from the pump to the filter and put the check valve in the line, so water can’t run back into the pump if the power fails. Stick the filter to the glass with the suction cups and turn the pump on. A pump with adjustable output, like the Tetra Whisper AP150, lets you tune the flow.

Cleaning the sponge

When flow slows, take the sponge out and squeeze it a few times in a bucket of old tank water. Don’t rinse it under the tap; chlorinated water can kill the bacteria living in it. Then put it back.

Who should look elsewhere

A sponge alone won’t polish water or hold carbon in a heavily stocked large tank. Pair it with a hang-on or canister filter there. For smaller tanks, the hygger double sponge filter is a better size.