Review on 🐠 Superior Replacement for Penn Plax Cascade 700/1000 GPH Canister Filter - 1 Pack Bio Sponge for Aquariums by Jennifer Davis

Nothing fancy, it's a mechanical filter media for a canister filter. It works exactly as advertised. It fits perfectly with your cascade filter and is quite durable. I bought this as backup media that came with my filter, but as long as I'm using the two original gaskets I got, I hose them down every week when I clean the filter. I'd say that with care you could probably last at least six months on one of these (I'll use 3 months with no noticeable wear), if not longer. They're so cheap it doesn't hurt to have a box with you as a backup.