ok, i'm using coco for the 1st time myself...soon to be re-potting mine into 11litre pots for 12/12, there in 6litre ones at the mo and seem thirsty as fuk, i'm giving them a litre every 2 days, does that sound about right to you? check out the start of my journal mate there 10days under 1600w....things should get interesting soon 
https://www.rollitup.org/grow-journals/313678-first-attempt-growing-coco-under.html#post3929748

https://www.rollitup.org/grow-journals/313678-first-attempt-growing-coco-under.html#post3929748