Features:

1, From Hollow Particles, 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, Hollow design, porous and will be good for Microbial reproduction.
6, Long life time. The little holes are not easy to be blocked.

Specification: Color: Colorful
Diameter: about 0.7~1cm