Water Molecules
Water molecules consist of two hydrogen atoms and one oxygen atom arranged in a triangular structure connected by covalent bonds. Water molecules can form hydrogen bonds and tend to cluster together. A cluster of 3–6 water molecules is called small molecular cluster water, while clusters of 10 or more form large molecular cluster water.
Small molecular cluster water possesses exceptional permeability, diffusivity, solubility, and metabolic capacity. It passes through cell membranes more easily, enhancing water exchange inside and outside cells, eliminating free radicals, harmful acidic metabolites, and various wastes, thereby promoting cell growth and vitality.
Water Hardness
Water hardness refers to the concentration of calcium and magnesium ions, measured in ppm (1 ppm = 1 mg/L of CaCO₃). Water with little to no calcium and magnesium ions is soft water; otherwise it is hard water. Total hardness of 0–30 ppm is considered soft water; above 60 ppm is hard water. Premium drinking water should not exceed 25 ppm, and high-quality soft water should have total hardness below 10 ppm. WHO standards recommend moderately hard water for health.
Water Conductivity
Dissolved salts in water exist as ions, giving water its conductive properties—measured as conductivity. Conductivity reflects the salt content of water and is a key indicator of water purity. Conductivity is directly proportional to hardness: the harder the water, the higher the conductivity; the purer the water, the lower the conductivity.
Dissolved Oxygen Content
Dissolved oxygen refers to molecular oxygen dissolved in water. Healthy drinking water should contain no less than 6 mg/L of dissolved oxygen. Dissolved oxygen represents the self-purification capacity of a water body. When organic pollution depletes oxygen faster than it can be replenished, anaerobic bacteria proliferate, causing the water to turn black and emit odors.
Water Turbidity
Turbidity measures the degree to which suspended matter in water obstructs light transmission. Suspended matter typically includes soil, sand, fine organic and inorganic particles, plankton, microorganisms, and colloidal substances. Increased turbidity from human and industrial wastewater indicates deteriorating water quality.
Water pH
The pH value of water represents the negative logarithm of hydrogen ion concentration, indicating acidity or alkalinity on a scale of 0–14. Water with pH below 5 is strongly acidic, 5–6.5 mildly acidic, 6.5–7.5 neutral, 7.5–9 mildly alkaline, and above 9 strongly alkaline. Only naturally neutral water is suitable for long-term consumption.