4 inches is too far away. CFL lighting is impossible to burn plants with unless they are 1cm away from your plants. CFLs do not produce as much heat and the intensity when compared to HID/HPS etc.. I can safely tell you to move your lighting closer to your plants, 1' - 1.5' inch close to the plants, not 4 inches. 4' is too far. CFL will loose its intensity VERY VERY fast when they are distant from the plants.
How many watt's do you have in the grow tent? You need at least 150w per plant with CFL.