Samsung Lm301b/h are very good diodes but there are others that are very good as well. I run spider farmers and are very happy with them, you should get years of use out of them. They’re supposed to run for 50k hours. A year of 12/12 is <5000 hours, a year of 18/6 is 6500 hours. Unless you’re planning on scaling up your operation, 3 sf1000 in a 4x4 is plenty of light and should last you 5-10 years