Same here. Have never seen any algae on the rocks the only place it grows is in the sump and on the glass in the display scrap once a week. Working on a diy ATS right now fixing your post some pictures. Trying to slow growth at the moment zoas are growing into the frag rack and euphylia are splitting heads so running out of room so have lowered the alk over the last two months and working on lowering nitrates from 10 to 5 basically switching my coral from growth mode to color mode. This is a recent FTS. Currently working on a 110 30’ deep with 55 gallon sump with rocks still curing. Unable to view the attachments you posted
Looks really good. I wouldn't mess with the water parameter changes to slow growth. Seems risky to me. The other aquarium looks ugly compared to a waterbox.