I Use botanicare cns-17 line and I'd say under a 600 or 1000w a good range is 700 for veg and climb to 1000 for flower. Not including the ppm of the tap. So including 300ppm tap water youre looking at 1000 veg- 1300 bloom max. PH never above 6.0.... more like 5.5. This is my experience with DWC not sure about other hydro methods. If you flower with PH above 6.0 the bud formation seems to be massively stunted.