Hmmm...i would rent a par meter if you can.... How large is your aquarium?I have 2 Kessil 360we leds. They are about 8 inches above the water and the nems are about 10 - 12 inches below the water. The lights run for 12 hrs. Ramping up to 60% peak intensity. I have kept this schedule for over a year. Only recently bumping up intensity from 55 to 60%. I did this a few weeks ago to see it it helped the nems.



