There is no universal filter. Two properties with the same equipment can get very different results because their water is different. Treatment selection is a response to test data plus intended use.
Step one: test
A laboratory analysis identifies what is actually present — suspended solids, hardness, iron and manganese, dissolved solids, and microbiological indicators. Without it, any specification is guesswork.
What each stage does
- Sediment filtration — removes suspended particles and protects downstream equipment
- Carbon filtration — improves taste and odour and addresses certain organic compounds
- Softening — addresses hardness that causes scale in geysers and appliances
- UV treatment — targets microbiological risk, and requires clear water to work properly
- Reverse osmosis — reduces dissolved solids and specific contaminants, usually at point of use
Intended use changes everything
Water destined for irrigation has different requirements to water destined for drinking. Specifying potable-grade treatment for the entire property when only the kitchen tap needs it is a common and costly mistake — as is assuming irrigation-grade water is safe to drink.
Plan for maintenance
Cartridges, media, membranes and UV lamps all have a service life. A system nobody maintains eventually performs worse than no system at all, because it creates false confidence. Confirm the consumable schedule before buying.