Choosing the right system
Making tank water safe to drink
Rainwater collected off a roof isn’t treated the way town water is, so if you drink from your tank it’s worth making sure it’s safe. It follows a simple order: keep the muck out, filter it clear, then disinfect. Grewa doesn’t sell a drinking-water system yet, so here’s the honest how-to.
Keep contamination out first
The safest water starts at the roof: a leaf guard and first-flush diverter, gutters kept clear, and a screened, sealed tank inlet and overflow to keep out leaves, animals and mosquitoes. Cleaner input means far less to treat.
Filter, then disinfect (the order matters)
Sediment first (a spun or pleated filter) to take out grit and cloudiness. Then, for taste, carbon. Then disinfection to kill anything living, commonly a UV steriliser. UV only works on clear water, which is why filtering comes first, cloudiness shadows the bugs from the light. Chemical disinfection (chlorine or similar) is the alternative.
When to be extra careful
If your tank has had contamination, a dead animal, flood water, an algal bloom, or if anyone in the home is very young, elderly or unwell, follow your state health department’s guidance closely, or use an alternative supply until it’s tested. When in doubt, boiling water for drinking is a reliable fallback.
How to find the right one today
Search along the lines of "rainwater UV steriliser drinking water Australia", or use this prompt to spec a treatment train:
I drink water from a rainwater tank in Australia and want to make it safe. The water is [clear / a bit cloudy / stained]. What treatment train should I install, in order (sediment, carbon, UV or chemical), what micron ratings and UV rating should I look for, and what maintenance does each stage need?
Where Grewa fits
A drinking-water range is on our roadmap, designed to work with the pump and the app. Until it lands, the sequence above, keep it out, filter clear, disinfect, is the accepted way to make tank water safe.
Safety: If you suspect your tank water is contaminated and you drink from it, don’t rely on it until it has been properly treated or tested. Follow your local health authority’s guidance, and boil water for drinking when unsure.
Common questions
Is rainwater not already clean?
It starts fairly clean but picks up whatever is on your roof and in the tank: dust, bird droppings, leaves, the odd animal. For drinking it’s worth filtering and disinfecting; for the garden or laundry it’s generally fine as-is.
UV or chlorine?
Both disinfect. UV leaves no taste and no chemicals but needs power and clear water and only works at the point of treatment. Chlorine treats the whole tank but leaves a taste. Many drinking setups filter, then UV, at the kitchen.