I'm not sure what is iws sytem, it sounds like a DWC, the best way to grow roots quickly is to make a flood and drain, raise and lower water level to keep the netpot moist and aerated, do it as much as your timer allows if possible every 1/2 hour. if you cant do that another way is to keep water level just touching the bottom of the growrocks in netpot. you may need to handfeed depending on size of netpots, the more you keep the growrocks moist but not submerged, the faster root growth. you also need to give them ferts in the right amounts and aerate your res well