Volcanic stone (commonly known as pumice or porous basalt) is a functional and environmentally friendly material, which is a very precious porous stone formed by volcanic glass, minerals, and bubbles after a volcanic eruption. Volcanic stone contains dozens of minerals and trace elements such as sodium, magnesium, aluminum, silicon, calcium, titanium, manganese, iron, nickel, cobalt, and molybdenum. It is non radiative and has far-infrared magnetic waves. After a merciless volcanic eruption, after tens of thousands of years, Humans are increasingly discovering its value. It has now expanded its application fields to fields such as architecture, water conservancy, grinding, filter materials, barbecue charcoal, landscaping, soilless cultivation, and ornamental products, playing an irreplaceable role in various industries. The characteristics of volcanic pumice (basalt) and the physical properties of volcanic rock biological filter materials.

Appearance and shape: No sharp particles, low resistance to water flow, not easy to block, evenly distributed water and air, rough surface, fast film hanging speed, and less prone to microbial film detachment during repeated flushing.

Porosity: Volcanic rocks are naturally cellular and porous, making them the best growth environment for microbial communities.

Mechanical strength: According to the national quality inspection department, it is 5.08Mpa, which has been proven to withstand hydraulic shear effects of different strengths and has a much longer service life than other filter materials.

Density: Moderate density, easy to suspend during backwashing without material leakage, which can save energy and reduce consumption.

Biochemical stability: Volcanic rock biofilter materials are corrosion-resistant, inert, and do not participate in the biochemical reactions of biofilms in the environment.

Surface electricity and hydrophilicity: The surface of volcanic rock biofilter has a positive charge, which is conducive to the fixed growth of microorganisms. It has strong hydrophilicity, a large amount of attached biofilm, and a fast speed.

In terms of impact on biofilm activity: As a biofilm carrier, volcanic rock biofilter media is harmless and has no inhibitory effect on the fixed microorganisms, and practice has proven that it does not affect the activity of microorganisms.

The role of volcanic rocks is 1: active water. Volcanic rocks can activate ions in water (mainly by increasing the content of oxygen ions) and can slightly release A-rays and infrared rays, which are beneficial for both fish and humans. The disinfection effect of volcanic rocks cannot be ignored, and adding them to an aquarium can effectively prevent and treat patients.

The role of volcanic rocks is to stabilize water quality.

This also includes two parts: the stability of pH, which can adjust water that is too acidic or too alkaline to automatically close to neutral. The stability of mineral content, volcanic rocks have dual characteristics of releasing mineral elements and absorbing impurities in water. When there is too little or too much, its release and adsorption occur. The stability of PH value of water quality at the beginning of Arhat and during coloring is crucial.

The function of volcanic rocks is to induce color.

Volcanic rocks are bright and natural in color. They have a significant color attraction effect on many ornamental fishes, such as Arhat, Red Horse, Parrot, Red Dragon, Sanhu Cichao, and so on. Especially, Arhat has the feature that its body is close to the color of surrounding objects. The red of volcanic rocks will induce Arhat’s color to become red gradually.