Crystal Alum

Traditional alum crystal used for clarifying raw water.

Alum in traditional crystal form, still the most widely recognised water clarifier in Nepal and still in steady demand for tank and small-system treatment. Suspended particles that would otherwise stay in the water indefinitely clump together and settle out. It remains popular because it is inexpensive, familiar to operators, and does not require the dosing equipment a plant-scale coagulant would.

• —Clarifying raw water in tanks and small systems
• —Settling suspended solids in stored or supply water
• —Community and household-scale water treatment
• —Pre-treatment before filtration or disinfection

Store dry and sealed, as crystals absorb moisture and clump. Dissolve fully before dosing and allow adequate settling time. Alum consumes alkalinity as it works, so very soft water may need alkalinity correction alongside it.

Crystal Alum is also sold and searched for as Alum, Aluminium sulphate, Phitkari and Potash alum.