Im using canna classic flores a+b, rhizotonic, tap water, and ph adjusted to 6.5 60%-40% coco + perlite in 3.7gal pots. Hipar 600w 400v ballast Powerplant 600w 400v hps bulb 6 inch air cooled hood Intake 6 inch inline fan. (Pulling air from the next room over which is aircon.) Exhaust 6 inch can fan. (Im making a stealrh box over my window to exhaust. For now heat just dissipates throught the house.) Huge canfan carbon filter( I'll hang it later) Tent is 1.2m × 1.2m × 2m 16/8 lights on off Pineapple chunk, money maker, green crack all are photoperiod. Plants are one month old from seed today.
As long as I've got the ph in reasonable levels im not worried. Im only using this dropper test kit. I just bump it down a bit lower than the green ph 7 colour on the chart.
You should be feeding between 5.7 and 6.3ph for coco/perlite and feeding daily or twice daily at Lower ppms for fast growth