Suspended solids are removed by scrubbing candle and scrubbing wears away ceramic material. Candles are relatively expensive. Yes Relatively easy to distribute and use, particularly in emergencies. Not locally available in many developing countries, have to be imported. Expensive for long term use.
Dose depends on organic material, etc in water.
Available chlorine in tablet can decline with age. Adequate contact time required. Rapid sand filters Use coarser sand and higher flow rate than slow sand filters to remove impurities by sedimentation, adsorption, straining, chemical and microbiological processes. Suspended solids especially after coagulation and flocculation. Yes Relatively small and compact.