Light only add to their stress.
if u on the light for too long, u may find them "emo" at one corner. What i do is if i on the light, i will make sure 50% of the tank top is cover with a black board so that they can hide under shade.
If i dont cover the top, its only for viewing and should be less than 10mins before the fish emo. Well at least thats for my fish.
hope it helps in some ways.
Ohh I think mine is FL/PL.