Only thing that could help is a light box/canopy over tank, inside painted white. Basically takes all that light you see reflecting off water and lighting ceiling above and around tank and redirects it back into tank as kind of a soft fill flash. Think of it way photographers use a a soft reflector to fill in shadows.
You can just go by some white foam core and prototype a canopy, tape it together and see if it helps. Itís a very subtle light. Where it will help most is out along outer edges, especially along front where fish will now be getting a soft light hitting them from front/above where led lights are currently are only hitting fish from rear.