I install shelf brackets on the wall above the tank using Molly Bolts in the
drywall or grabber screws into a wall stud(if available). It only takes one Molly bolt/grabber screw per bracket. Then
I hang the light with the hanging kit or with decorative chain and "S" hooks. That
way I can raise or lower the light to any height. Apartment managers
don't care about Molly Bolts because they are hardly noticable when the
shelf, bracket and bolt are removed.
I have extra chain, screws and Molly Bolts I'll give you, and when you come over you can see how it's done. I have 3 light fixtures installed this way for 4 of my 6 tanks comprising a ~200 gal coral farming system.
Aloha
808-345-1049 in Murray
Molly Bolt
shelf brackets