Review on Enhance Filtration Efficiency with ALEGI 4 Pieces Aquarium Filter Foam Sponges Pad - Premium Fish Tank Bio Sponge Coarse Sheet Filter Media Pad - Cut-to-Size Foam for Optimal Pet Filters (9x9x1 Inch 4 Pcs) by Rob Vizitei

When I first bought this product I was trying to make my own aquarium filter. But after soaking the sponge for a few minutes, I noticed a few particles came out of the sponge. At first I thought it was chunks of sawdust from the factory as could be seen from the sealed packaging but after further dipping the sponge in water and squeezing out the water along with what I assumed was sawdust from the sponge. I noticed that not only did more particles come out, but the sponge also became thinner than it originally was. That's when I realized that the sponge disintegrated in the water and the particles were pieces of sponge floating in the water. your fish!