I start mine with just water for a week to 10 days then I go to 200ppm for a week then to 400ppm and do this untill I get to 800ppm then I start backing off on the nutes,a week before harvest I change the res to just ph adjusted water and thats it,I grow in dwc and my first grow taught me alot,I dont run the high end on the nutes,my plants grow just fine with lower ppms and I have less problems. good luck