First time indoors\feeding questions

[first time in]

I need some exp. info on when to change from veg to bloom, based on forcing time. I've done my under trimming. plants are 3'. right now I'm still using age old grow @1 oz. per gallon, each plant gets this 1/2 gal /day. 18 hrs under 4 1000w grow lux. they were originaly transplanted from 6' pots using black gold potting soil until under 1 400w along with 4 4' florecents in a starter room then moved @ 18" to thre gallon qrow pot using a pearlite/vermiculight/cocco fiber. at this time I began using soluable hydro liquid food.[age old grow].initialy, they were only fed at full rate every other day. After the "new huge" leaves made up the top two thirds, i trimmed the now necrotic unergrowth, leaving a sixteen Inch canopy. Then I set the plants at three under each 100W and cloned. Now My question is; when do I switch to bloom based on maximizing my canopy and yield?