So I know a bulb last quite a long time, but I like to have a back up. Looking around the web I find there are basically two sorts- agro kinds and regular ones. Is there really a big difference. the prices are all over the place. I compare and the only difference between 400 watters is 50000 lumens vs. 55000 lumens. 10 percent is ten percent but does that warrant spending three times as much? Has anybody used both and noticed a difference?
