Review on 🐠 Ceramic Filter Rings for Aquarium Filtration - 140 Count - Compatible with C-Series and Magniflow Filters (PA11484) by Leanne Steltz

They are 5 times cheaper than the popular "Eheim Mech" ceramic rings and work the same way. This product is primarily a mechanical pre-filter. It breaks up larger dirt particles and traps them on ceramic surfaces. You must perform the filtration with a fine mechanical filter such as a sponge or thread. Although the rings have some biological activity, they are NOT considered biological filter media. You have to have some kind of biological environment in your system. So the ideal setup for a healthy aquarium would be these ceramic rings, followed by a fine mechanical filter (pad, sponge, thread) and then a biological carrier.