i know its late, but someone reading this thread might get the wrong idea. so i thought i might share what i learned. All fish need a way to distinguish between day and night as fish rest(sleep), so make sure the lunar lights or moonlights are not too bright. if you cant tell, then just make sure, the fish are resting and not playing after moonlights are on. if they are playing, then you should give them total darkness. Heres what i do
reg light on for 10 hours
then moonlight turns on for 2 hours.
then total darkness.