not sure which led you are using but something I discovered is I had mine way too far away. even when I checked before with a meter and it seemed alright. but really I was several inches away from the prime spot it seems. looking for better outcomes down the road. i have also seen a difference between lights. the xs series definitely gets them frostier and the new AC light also seems to be a light they are liking. my older p series is noticeably lacking but still does the job just slower. and the ks also does a good job and the plants like it too, but closer, much closer than i thought. but that's where the plants want it to be and they are loving it. so maybe there's a distance issue with your led? But if electric was cheap I would be using my HPS.