Most off-grid homes rely on a tank: filled by rainwater, a borehole or deliveries by lorry. The tank size decides how long you can go between fills; the filtration decides whether the water is safe to drink.
Work out daily use (a careful household might use 100–150 litres a person), then the longest gap you need to cover. Underground tanks keep water cool; above-ground tanks are cheaper and easier to inspect.
For drinking water, start with a laboratory test, then choose filtration to match: sediment filters, carbon, UV and reverse osmosis each deal with different problems.
Questions to ask before you sign
- What size do you recommend for my use, and why?
- Is the tank food-grade for drinking water?
- What base and access does it need?
- What filtration do you recommend after a water test?