One thing to remember with running kessil's is that the way they're designed they won't ramp up from 0 and ramp down to 0. I had to set my program to start / end at 15%. If you go lower than that you'll get flickering.
here's my settings and everything in the tank seems very happy
Intensity:
Sunrise: 15-62%
Daylight: 62%
Sunset: 62-15%