Black Semi-Circle Single-Hole Aquarium Filter Sponge

Step 1: Installation

Begin by removing the filter sponge from its packaging and rinsing it briefly under dechlorinated water to eliminate any loose particles. Position the semi-circular sponge into your half-round filter housing with the single hole aligned to the intake tube. The contoured half-moon shape seats snugly against the curved walls, preventing water from bypassing the foam.

Step 2: Daily Usage

Once installed, the open-cell structure immediately begins trapping debris while providing a vast surface for nitrifying bacteria to colonize. The stackable layered design allows you to add multiple sponges vertically, each layer increasing biological filtration capacity without restricting flow. Water passes evenly through the full thickness of the foam, ensuring mechanical and biological filtration work in tandem.

Step 3: Routine Cleaning

Every two to four weeks, remove the sponge and squeeze it gently in a bucket of tank water — never tap water, as chlorine will kill the beneficial bacteria. The resilient black foam rebounds to its original shape after repeated compression, maintaining consistent pore geometry wash after wash.

Step 4: Replacement

With proper maintenance, each sponge performs effectively for six to twelve months. When the foam no longer rebounds after squeezing or flow resistance remains high even after cleaning, it is time to replace it. To preserve your bacterial colony, run the new sponge alongside the old one for two weeks before removing the spent unit.