Put timers in your tanks. Mine goes into steps, dim light first for them to adjust and then the bright light later. Unlike us who can totally dim our sight with the use of our eyelids, fish do not have this and the sudden appearance of light overwhelms them. All my electrical apparatuses are actually timed: wave makers and lights. I am starting to think my fish have been accustomed to them. Today, I saw my GT getting below the wave maker so he won't be blown by it while the PB's lining up in front of it acting like there is a race.