Back when I had a 8 bulb Tek light on my 100gal I had Z's and P's roughly 5-8" just below the water's surface. The Tek was only 6" or so above the water surface. Z's and P's were acclimated slowly to the light and move up accordingly.
Really old pictures.
Same with my A360, I had Z's and P's front corner of tank roughly 6" below surface with A350 back them at Max on both blue and white.
See the Z's and P's on top right which is only 6" or so below water surface.
