you can either mix everything together at once or mix your nutes in each bucket. lets say you had (4) 5 gallon buckets, so 4 gallons of water in each, totalling to 16 gallons for all 4 buckets. now lets say your nutes sayto use 5 ml per gallon of grow, micro, and bloom for example. You would be adding 5ml x 16 gallons = 80 ml of each, now add to your distilled or R/O water, THEN pH down. then fill your buckets to your fill line. And tellno1, DWC is way more forgiving than soil because like any hydro setup at the first sight of nutrient burn you can flush and and reset your res with virtually no stress at all from the nute burn. DWC is more time consuming but with better results quicker