Just got the reverse osmosis unit installed yesterday and the water after being treated reads 40 ppm. Would this be safe for all CPs? I've heard everything from under 100 to under 20. I do have quite a few undrained pots of plants also. Would this be a problem? Previously I have always used distilled water. This is also water softened with potassium, so I don't know if any amount of the potassium left over would be a danger for CPs.
I'm also curious, for those of you with reverse osmosis units, what is your TDS reading before and after treatment? Mine started at around 400 ppm and is down to 40 ppm today.