What size and wattage LED light will I need

Hey bro .... Your budget ? ... The best qualità/price Is TS Mars hydro .. for the most efficente see Migro on YouTube ... Hps 1.2 Mars 1.6 Most efficente 2.5... Low efficent Is the old school led .. like viparspecrta...or blurple

basically a metere squared.. so you can look straight up on a DLI chart -- upto 45 without CO2 and 65 with. minimum you want 500umol/s to bloom in that area.. preferably closer to 1,000. 3.5*3.5 = 12.25... 10.764 ft^2 = m^2 so 1000 * 12.25/10.764 = about 1140umol/s as your ceiling. This is theoretical and also likely slightly higher than what you want, so it probably evens out about right. 500* 12.25/10.764 = about 570. This is for 12 hours of bloom. If you only do autoflowers you can concentrate on a 18-24 hour length. With 50% or more hours, you take off 33%. So.. Min 570 *.66 = about 380umol/s max 1140 * .66 = about 750 umol/s you provide that over 18 hours to an autoflower without adding CO2 and that's as good as you can get without harming your plant. Don't go below ~400umol/s for this area over 18hours. If you add co2 to 1300-1400ppm.. your max over 12 hours is now 1500umol/s per m^2... same minimum.