[PorkchopExpress]

the longest i was able to go was 5 days before my sps started dying (my goal back then was 7 days)...i had to do 3 days, then 1 day of reduced light, then 2 days before i started noticing some stn and i stopped...of course back then my sps stn'ing could have been a multitude of other factors such as H2O2/UltraAlgaeX/Dinoxal dosing and many other things i was trying

i can do 3 days with absolutely no problem, in fact they seem to actually like a 3 day lights out once in a while - when i uncover the tank their polyps are all out, no signs of color loss, and they've continued to grow during the lights out

fish are fine depending on what you have...i have anthias so when i do lights out, i will turn on the blues every 2nd night for 15-30 minutes just to feed him and any others that want to eat then cover the tank again...but generally they are fine for a few days without any food

ps - as mentioned above, i've found blackouts to be temporary bandaids...they always came back afterwards, sometimes stronger than previously although i never tried more than 5 days...i suppose if you blackout for long enough, anything photosynthetic would die including most dinos