MARINE PURE BLOCK 20 X 20 X 10 CM

Great if you have a large filtration need.

Removes ammonia, nitrites, and nitrates
Primarily designed to provide deep anaerobic denitrification zones in passive systems.
Excellent substitute for live rock as it reduces nitrates more efficiently and without harming the environment.
Recommended for use in sumps, stacked, or in extra-large filters.
Its surface area for bacterial settlement is equivalent to 2,150 m2