Highlights:
● Fish has a strong color effect on the dark sand background
● Black corundum mostly contains of carbonized silicon
● Corundum sand helps to maintain water temperature stability
● Won't produce any dust by disintegration, very hard to disintegrate (under normal use almost no disintegration),will not release substances to impact water quality
● Suitable for both soft and hard water fish
Disadvantages:
● Small particle size results in narrow gaps in the substrate.
● The substrate itself contains no nutrients, so root fertilizer must be added when planting aquatic plants.
● If accidentally sucked into the filter, it can severely wear down the impeller blades.