u need 2700 k rating cfls fo flowering (more red, or orange light beam) and 6500 k rating cfls for vegging(more bluish beam)but a mix works good my 3 26ws are fo 1-2 plants to harvest but very small personnal ones becuz i have low low low hight almost like a pc case but those lights should work for 1 plant they ll WORK but higher wattage the better just watch ur heat, leafs for yellow or burn spots, and the hight of the light bulbs...most people say the un gives off 10,000 lumens right? and u can grow a big 5 footer or even bigger with the sun so if u get 10,000 lumens of cfls u could probably grow a 5 footer inside but the golden rule i was told is 5,000 is for a pretty good plant so calculate ur lumens per cfl times it by the number of cfls u have n there u go u probably have around 4,500ish with those 2 42watters