What is the function of coral sand?

Coral sand, that is, coral or shell fragments, has the characteristic of continuously releasing calcium carbonate. Its biggest feature is abundant micropores, which are suitable for the survival of a large number of biochemical bacteria and can be used as filtration materials. It is a fragment of coral or shell, which has the characteristics of continuous release of calcium carbonate, with different particle sizes and various specifications.

Because the sea sand contains alkaline substances, the pH value after filtration is generally 7.0 ~ 8.5, and the continuously released calcium ions and magnesium ions can provide high hardness and stable pH value for the survival of marine organisms, so it is suitable for seawater filtration system for cultivating marine fish.

It needs to be replaced after 8- 16 months of use. Because of its rich pore structure, it can also be used as a carrier of biological filtration system to cultivate a large number of nitrifying bacteria. It belongs to marine natural filter material, and its biggest feature is that it is rich in micropores, suitable for a large number of biochemical bacteria to survive, and can be used as a filter material for laying the lower (inner) layer.

Extended data

Coral sand is used instead of natural river sand in concrete mix design. The flexural strength, compressive strength, splitting tensile strength, drying shrinkage and early cracking resistance of coral sand concrete are systematically studied, and compared with river sand concrete with the same mix ratio.

In addition, the durability of coral sand concrete, such as chloride ion penetration resistance and carbonation resistance, and the microstructure of hydration products are also analyzed. The test results show that the compressive strength of coral sand concrete is lower than that of river sand concrete, while the flexural strength and splitting tensile strength are similar.

Coral sand concrete has better drying shrinkage, early crack resistance, chloride ion penetration resistance and carbonation resistance than river sand concrete. Coral sand has convex and concave pores, which makes the bonding force of its interface transition zone greater than that of river sand concrete, and greatly improves the structural properties of its interface.

Coral sand plays the following roles in fish tanks:

1. Coral sand is mainly composed of Ca, which can adjust the PH value of water in fish tanks. ?

2. It can beautify the waves and fix the scenery.

3. It is beneficial to the reproduction and survival of aerobic bacteria and denitrifying bacteria.

Reference: Baidu Encyclopedia? coral sand