Why Buy It Rather Than Make It
Plenty of people reading this already make their own pure water, and for some of them that is the right answer. It is worth being straight about when it is and when it is not.
Producing your own means an RO unit, a resin vessel, somewhere to put both, and the discipline to test the output and change the resin before it starts letting minerals through. The running cost looks low until you count the resin, the water you send down the drain, and the morning you spend re-doing a row of houses because the TDS crept up without you noticing.
Buying it is 4.4p per litre with nothing to own, nothing to service and no space taken up in the van or the garage. If you are on the road anyway, and there is a station on your route, that is usually the cheaper hour.
If you already have a system that works and the space to run it, we are not going to pretend otherwise.
4.4p per litre, the same whether you take twenty litres or a full tank. It is on the kiosk screen before you dispense.
No membership, no minimum spend, and a VAT receipt for every fill.
No RO unit to buy, no resin to change, no vessel taking up half the garage, and no capital tied up in equipment that needs replacing.
When a station needs maintenance, that is our problem and our cost.
The point of buying rather than making is not having to test your own output. Water leaves our stations at zero total dissolved solids.
A station that has drifted comes offline rather than quietly selling you poor water.
High-flow dispensing sized for a tank in a van. You pull up, fill, pay and go.
No production run to plan around and no waiting for a system to catch up before an early start.
A tank in the van and nothing else. For anyone working out of a flat, a rented unit or a shared yard, that is often the whole argument.
Reverse osmosis always rejects some water. Doing it at scale, on equipment that is monitored and maintained, wastes less of it than a domestic unit run until something goes wrong.