Thanks for the reply. Yea my plan was to mainly switch my houses over to start with and stick to my bungalows the traditional way. I'm lucky that about 50% my work is bungalows.First of all @Halesy , my suggestion would be to change customers over in stages. If you don't then it will drive you crazy doing it all one time.
You purchased a tds meter, and yes, your water is hard. That's the first thing to buy. Secondly, you need to buy a water pressure gauge (Screwfix sell them) to see what your water pressure is from your tap and, thirdly, you need to measure how much water comes out of your tap in litres per minute.
Look at PF and copy their static system
https://purefreedom.co.uk/products/...reverse-osmosis-system?variant=43780579786926
You will need a transfer pump/submersible pump and transfer hose. I added a float switch and normally closed solenoid valve. When the tank is full the solenoid valve closes ad switch the water supply to the r/o off.
I purchased a used IBC tank for £50. It was local, so I collected it in my van.
Iv got a plumber mate who is going come round and test my water flow over the weekend.
That tank set up is the original one I was considering. Seems like alot people use pure freedom