I haven't visually inspected the water that flushes through the R/O system/filter, but I service and have installed on several homes with R/O systems and the zones that are not run through the R/O are a real mess, leaving me to think that the flush water coming out of the R/O filter is going to be pretty messy and full of particles that would clog a drip system unless it had some serious self flushing filters. I would also question the wisdom of running the flush part of the system on trees...concentrated iron? I would want to test the water coming out of the flush part, sure there is no salt, but what other concentrates? I would also test the soil. I am pretty sure you are in an alkaline area, but you don't want to o.d. on iron. I am sure Kiril can chime in on this stuff.