i feed 4 times a day when on 18-6 and 3 on 12-12, i set my pump timers first feed 2 start when my lights come on, my tables fill in 6 minutes, (example) first feed at 1130am off at 1136am, second at 430pm off at 436pm third at 930pm off at 936pm, forth 230am off at 236 am, dont feed when there asleep, only use expensive name brand pumps i use fish tank powerheads, if your pump burns out and you dont catch it your plants die (its happend 2 me), also your reserve must be lower then your table or it wont drain DONT use the barrels use the rubbermaid 1s with tops or the hydrostore 1s with tops, you can get every thing you need from a hydro store they have the tubing the nuts and the over flow pipes/screen tops, use the white trays the black1s are junk