It doesn't make sense, if your water is at 60-70 then surely after Ro you should get it low enough to not need di? It'll be cheaper to pay for water on a metre than it will for resin, especially if your putting water in that high!!!!!! Maybe you need to think about keeping it!
How much water do you use each day?
i clean with pure water, i dont clean with water thats 7 or similar if i can help it, if i use and ro then i create waste water, im on a meter and all the water i use i pay for so im not willing to pay for stuff that im flushing down the drain. I prefer to use di only as 1. its cheaper. 2. its instant so it means i dont have to leave my static running 24 hours a day and therefore i also save electricity as i dont have my pump running