YEE Natural Volcanic Rock Aquarium Filter Media, 500G

The rough surface allows fast attachment of culture bacteria and the microbial membrane does not fall off easily upon rinsing or washing. - Cause ions activation in the water, increasing the oxygen ions content.
The volcanic rock has low resistance to water flow, it does not cause blockage.
Allow culture of digestive bacteria (nitrifying bacteria)
Adsorption of harmful bacteria, and heavy metals such as chromium and arsenic.
Stabilize the water pH value, and provides water filtration and water quality control.
The red colour of volcanic rocks will induce the red colour of the fish gradually.