Review on Efficient Bio Sponge Filter Media Pad: Powkoo Filter Foam Sponges - Ideal for Aquarium, Fish Tanks, and Pond Canister Filters! by Diane Hubert

Bought these sponges to improve the filtration of my hanging aquarium filter, specifically the Whisper 10i. Arrived quickly in an interesting Chinese packaging. After I washed them and put them in the filter, I noticed that a significant amount of veggies and other debris got into them, not just through the filter. The kit includes a large sponge and a good size fine sponge. Ultimately a great product that works well. It's been in my filter for a few days and it hasn't killed my fish so it should be safe. It's a sponge, not much can go wrong.