I don't mind some shimmer but some tanks at a LFS literally look like they are flickering on and off.Don't be a baby!
LEDs, Metal Halides, and sunlight will all refract light like that.
I like it up to a point! If it bothers you, decrease your surface agitation a little.
All kidding aside, I run 6 15 watt Bridgelux LEDs on my 65H, and the shimmer is a bit excessive. I have my continuous WC dripping into the tank, causing it.I don't mind some shimmer but some tanks at a LFS literally look like they are flickering on and off.
Even my 4 bulb T5HO had a bit of shimmer with a different outflow than I have now because the lights were raised so high. It didn't bug me but it would have if I had LED's.