i do flood and drain as well and i have a 600w HPS over one of my 2x4 tables and i use hydrotone as well but only in flower and i water 4 times in a 24 hours . For Veg ones i and ready to transplant my rooted clones i will soke my rock weel in water that is at the right ppm and ph for about 5 mins and then take my rooted clone and put it in the RW and put it in my veg tray and then i will only water 2 a day and only if needed then i will water one more time but thats only on really hot days and when i water its only for 20 to 30 mins and only flood the very bottom of the RW dont flood the hole thing cause then you well get root rot so just the bottom about half a inch or less . I also use organices in veg so i can juice the shit out of them i hit them with about 850ppm right off the bat and work my way up 1500ppm and some times 2000 ppm dipending on the strain and if it can take it but whats cool about using organices is you cant burn your plants with them . IN flower i switch to the flora GH serise lucause formula and i add some cow-mag and liquied cool bloom and start my ppm at around 700ppm and work my way up to about 1000ppm some times 1200ppm and i always come out with some killer smoke and good yeilds so if you have any qustions you want to ask just send me a pm and i will help you out the best i can . its always nice to take to some one who grows the same way and to see whats been working for then so good luck and let me know how it goes