I'm in amended soil and using CES nutes.
Definitely getting 2 more lights in the future.
I to like bigger pots and plants. I will be using 5 gal maybe smart pots.
Hmmmm how about 16 in 10 gal?
what sire said max the pot size out
if the plant is 120 grams and under a 3 gallon pot will work (5 gallon for those will be over kill and max the plant out with right feeding) ....1x1 or 1.5x1.5 footprint
if the plant is above 121 grams u want some where in the 7 gallon size 10 gallon would be better .......2.5x2.5 or 3x3 footprint
the amount of water the smart bags will hold
3 gallons under 1/2 gallon water
5 gallons about 3/4 gallon
7 gallon just shy of a gallon
(this is smart pot bags packed with soil ) ....the 10 gallon one i just used 1 gallon of water figure it holds about 1 gallon 1/3
now assuming this is not your first time running plants and u have basic feeding skills...10 gallon pots u should figure 3x3 foot print so that is a 4x3 that is 12 plants max with very little work/paths so i say go 9 that will leave u room for paths to water and work