oh yeah...got my disco lights up...sorry no pics; they don't show up all with my crummy camera...but let me assure you they look cool.
I got a Marina Hub with 3 Marina LED submersible units; they are fine for my size tank (16 inches high) and would do fine for yours too...nice thing, you put in the plug unit, you can buy different colours pretty cheaply and change it up to your current tacky fancy

I jest but my better half thinks they are tacky.
I think you are correct in them having no particular benefits in FW...they do however turn a big tank when the lights gone off into a tacky disco lit partytastic lightshow !