This thread has been a real eye opener for me, i didn't realise how good ive got it. I have a 1000l ibc in the garage and transfer to a 500l tank in van each night.
Bought a ro compact (or equivalent) from Pure freedom 18 yrs ago.(todays price £192 divided by 18 = £10.66 pa) I change the filters every 4 months (annual cost £54), the present membranes are bringing the tds down from 400 to just 3. Ive had them for 3 yrs (£56.13 x2 divided by 3 = £37,42 pa). Because the membranes are doing their job so well, i only use 1 bag of resin a year (£118,32 pa). I use a booster pump, which say lasts 3 yrs (£123.98 divided by 3 = £41.33 pa). So thats £261.73 per annum ie a fiver a week (prices include vat) without water charges if that helps Zesty. As for time, i bet i spend alot less time on the ro than i would travelling to collect water.