Check the listing for details. Aquarium Filter Media Porous Bio Ceramic Block for Fish Tank Sump Tank Pond. Condition: New. Listed at 8.99 USD. Notice: Please do not use immediately. Soak in water for half an hour before use. Feature: 1. Hollow Desing - Large Surface Area: Hollow design to increase surface area. Effectively improve the cleaning ability, adsorption capacity and the number of the beneficial bacteria 2. Honeycomb Shape Design: Porous surface good for bacteria to colonize. Enhance water permeability and adsorption capacity 3. Purify Water Quality, Remove Peculiar Smell : This powerful item can Removes Ammonia& Nitrites, Stabilize PH Value, Absorbs Odors/Heavy Metals/Toxins, effectively absorbs fish waste and debris, providing crystal clear water for fish to thrive, thereby enhancing fish immunity 4. Redusable Aquarium Filter Media: It can be cleaned and reused. Adopt protective packaging, safe and not fragile 5. Wide Application: Perfect for freshwater aquariums. Like aquarium filter, sumps tank and ponds. Crack into pieces to different size up to your needs Specification： Improves Water Quality and Clarity Large surface area for raising good stuff Media size each pc: 6.3x1.4x1.4 Inch Use in: Fish Tanks, Sumps, Canister Filter, Bakki Shower Filters, Trickle Filter, Hang on Back Filter, Aquaculture, and Koi Ponds. Safe for Pond, Freshwater, and Marine environments. Reduces Ammonia, Nitrites & Nitrates Work as mechanical and biological filtration. Promotes Beneficial Bacteria Growth