there are plenty of guys/gals on this site that didn't graduate high school, but built their own lights…..as a "practicing engineer" i would think u could build a much better light with a $1000.
i'm still trying to figure out how plant numbers matter??? size of said plants would be my question……..4 600's would be perfect for a 8 x 8' and work just fine for a 10' x 10'...
i use the hydro too. i get the cal/nit off amazon, lot cheaper. no epsom needed with my tap water. i use half gallon jug n put 300grams hydro in 1 and 200g in the other then mix equal parts to mix my nutes.