I run 2 seperate E&F systems and the plants start in 1" cubes then graduate to 4" cubes that get ste in the flood tray about 1/3 buried in Hydrotron. Tray floods 5 times a day for 15 min during flower and 6 times a day for 15 mins during veg. No problems noted so far and been running the 2 systems for about a year now. Only thing I see about RW is the salt buildup you can get from it but I do a good flush when I change from veg to flower then the last week in flower, when they are getting nothing but plain water, I flush mid-week also.