Rocks are beneficial in water filters primarily because they are porous materials that can filter out impurities and also release beneficial minerals.
Here's a breakdown of how rocks contribute to effective water filtration:
Filtration Mechanism
- Physical Filtration: Rocks, especially when used in layers of varying sizes, act as a physical barrier. Larger rocks trap larger debris, while smaller rocks like gravel and sand filter out finer sediments.
- Porous Structure: Many rocks have a porous structure that allows water to pass through while trapping sediment and other particulate matter.
Mineral Enhancement
- Mineral Release: Certain rocks, particularly those with mineral-rich compositions, release beneficial minerals into the water as it passes through. This can improve the water's taste, nutrient content, and alkalinity. This process can also replace unwanted ions, such as heavy metals.
- Examples: Some water filters use stones that are porous and filled with beneficial minerals.
Support for Biological Filtration
- Surface Area for Bacteria: Rocks provide a large surface area for beneficial bacteria to colonize. These bacteria can break down organic contaminants in the water, further purifying it. This is especially important in long-term water filtration systems.
Types of Rocks Commonly Used in Water Filters
- Sand: Very effective at removing sediment and turbidity.
- Gravel: Used as a pre-filter to remove larger particles.
- Activated Carbon (often derived from rock-based materials): Excellent at removing chlorine, organic compounds, and improving taste and odor.
- Zeolite: A porous mineral that can absorb ammonia and other contaminants.
- Mineral Stones (like Maifan Stone): Release beneficial minerals and adjust pH levels.
In summary, rocks are good for water filters because they provide physical filtration, surface area for biological filtration, and in some cases, release beneficial minerals into the water. Different types of rocks are used depending on the desired filtration outcome and the contaminants that need to be removed.
