how long is too long? light that is.

[mommahoss]

is it alright to leave my flourescent light on all the time? besides the whole algae issue.

 

[Lateral Line]

Fish need to rest - 24 hours of light is not natural in the tropics. There are also fish which a largely nocturnal. Additionally, if you have live plants, they will want a period without light to respire and exchange waste products of the photosynthesis process.

12 hours on 12 hours off.

 

[Tempestuousfury]

Your plants'll start wilting if they don't respire. It's just not worth it, and the fish will get really stressed out. As you've already noticed, fish don't have eyelids and can't close their eyes. The closest they get to sleep is a trance-like state, which is when the lights are off.

 

[Adrinal]

light timer rocks