im feeding 36 at a time. i use nutes, additives and ph, all by hand and four gallon pots. so i water everything from pre-filled (and rested) tap water in 5 gallon buckets. then i take the eight, 5 gallon buckets and refill them to sit out for the next feeding. everything takes def over an hour. maybe two hours, to mix nutes, feed and refill buckets. i only said 30 minutes cuz i didnt want it to look like a stretch, an exageration. ya know?
i just wanna point out that you can get a oz in saginaw for 100$ or less, or a qp for 300...I understand your way is legal, and hopefully better quality but unless you get caught during the transaction you'd be fine purchasing from a street dealer for half or a quarter the price if you can legally posess it...And i do not in any way suggest people do that, just a different perspective ...