My lights hang from simple white shelf brackets mounted several feet above the rimless tanks. Very unobtrusive.
White or chrome chain with "S" hooks makes for easy, frequent up and down movement. I get in the tanks often.
There are very fancy nice looking shelf brackets. Also nice looking wall mounted plant hanger brackets.
I use Molly Bolts, if the wall stud isn't in the right place. If/when shelf brackets are removed the Molly Bolts can be painted over, leaving hardly a trace. (these are the ones where you insert the molly bolt through a 3/8" hole in the wallboard, turn the bolt to expand the metal on the inside then remove and replace the long bolt with the item attached)
Aloha