Glass Tank Lids - defeats MH lights? vs Fish Splashing?

[StoutLager]

I have Hetal Halide lighting and glass lid on aquarium.

Is this a problem for the efficiency of the lighting?
If so, how much light am I losing due to reflection and refraction?
Is this possibily why I do not have coraline algea growing?

The other side of the coin - fish splashing.
I take the glass tank covers off and I get salt water everywhere. I cannot believe my fish are the only splashy ones.
Everytime I approach the tank (feeding time) a different one will jump or splash water everywhere. Then when I put food in, it happens again. Please advise.
(Med and Juv Blue Tang, Juv Ocean Sugeon, Flame Cardinal Fish, Bluehead Wrasse, Puddingwive Wrasse, 2 juv Spanish Hogfish)

 

[StoutLager]

It is almost like the perfect compromise would be a very large rectangular upside down plexiglass conical funnel which, when placed on the tank would not interfer with the lights, but all salt water and jumping fish would be channeled back into the tank.