250g Volcanic Rock Biochemical Ball Filter Media Nitrifying Bacteria House Aquarium Filter Accessories For Fish Tank Water Cleaning

Features:

1. From natural Volcanic Rock
2. Full of rich variety of natural elements and essential minerals and trace elements.
3. PH Neutral. Great help to restore the natural water quality, and provide the most suitable living environment for your fishes.
4. Won’t dirt water, absorb ammonia, and other toxic substances in water.
5. Porous and will be good for Microbial reproduction.
6. Long life time. The little holes are not easy to be blocked.

Specification:

• Material: Natural Volcanic Rock
• Color: Red
• Diameter: about 5-8cm