I wanted to know if our shrimp need to have a dark cycle, with lights out, in order to rest and stay healthy . Is it alright to keep the lights on at night if the shrimp are in a medium planted tank ?
Everyone needs "dark cycle" . Plant too. If you will light all day. At least plants will die. Shrimps should maybe hyde somewhere and rest, but will not be happy
I turn my tank lights off at night because I like them to have their quiet time while everyone else is sleeping. Lots of things go in my tanks during the dark of night...snail eggs are laid...shrimp moult...shrimp mate etc. I think it's important for them to have the cover of night to be able to do their thing.
I know some saltwater fish needs light/dark (day/night) cycle in order to trigger them to breed.
In my experience with shrimps (cherry reds, crystal reds, amano, tigers, blues, etc.), I have not seen that. I have light on 24hr and cherry red shrimps breed like "no tomorrow".