# Should I turn my tank light off??



## danibu

I've read around a bit and I have yet to see a thread or site that says anything about turning the tank light off at night. I know there are probably people who will say yes and some who will say no, but is it bad for my fish if I leave the tank light on 24/7?


----------



## serpa_man

yes it is bad if you leave the light on 24/7. the fish will get sick. i usually turn my tank light on when i get up and turn it off when i go to bed. Fish are just like us, they need to sleep. We need sleep to or else we will get sick. What i have read online was leave your light on anytime from 10-12 hours or less. just my .02.


----------



## snyderguy

No only is it bad for the fish but it's bad for live plants too. There is a difference between when they take in oxygen versus CO2. I can't remember which it is though, whether it's the take in CO2 at night and leave go of O2 during the day or the other way around.


----------



## Scotty00

It is bad for the fishes really. They will be tired of lights and it is not good for their eyesight too. It will stress them off. The heat from light also affects them. Do you like to stay under sunlight or any other bright lights the whole day? Definitely NO. :chair:

Darkness will make them sleep deeply. So switch it off when you go to bed. Let them also take rest.

But if you really want to turn it on for 24/7, try fixing LED. The heat will be reduced as well as it will look even nicer. You do not need to replace the bulbs always as it will not burn for several years.


----------



## chronoboy

I left my light on my 20g with all the fry in it on accident the other night and i went in thier in the morning and all the babies where trying to hide under the rocks, my guess is to sleep in the shade cause i know when i go in to the spare bedroom to feed them in the morning and turn on the light they are all sleeping ontop of the rocks, wich scares me somtimes cause two of the rams are deep sleepers all the other rams and angelfish will pep right up when i turn on the light but the two ram would stay laying on the rock and i thought they where dead at first but no just heavy sleepers.


----------



## Mr. fish

Actually you should only be keeping your lights on for 6-9 hours tops..

Light causes algae and like others said, your fish need to sleep too. Lets not even get into the electric bill!! lol


----------



## girth vader

In short, turn the lights off for 10 hrs/day.


----------



## Ghost Knife

I leave my tank light on for about 12 hours during the day. They seem to like it and I can see that they sleep during the night.


----------



## TheOldSalt

The endocrine system of a fish is controlled by photoperiod, so leaving the lights on all the time will really mess them up after awhile. Don't do that.


----------



## SGT Z

I sometimes go a day or two without turning the lights on at all. It's not natural for fish to swim in brightly lit water. I know my oscar will not sleep at all with the lights on.


----------



## ronmarsh99

yes it's bad as fish r like people they need to sleep plus you will be fighting green algae.


----------



## Mikaila31

I have some wild caught panda garras and these fish like to have their own individual cave or piece of wood. Whats amusing is with 6 in a tank they all know where THEIR one is, every night same fish in same cave. When ever I left the lights on till like 1am or something silly they would all still retire to their caves and go to sleep at the normal time. Plants I found will do the same if they have been on a regular schedule, then you leave the lights on like 5 hours longer one day. Plants will all still go into respiration mode despite light still shining. You can tell this easily with stem plants because the leaves are held pointing out during photosynthesis. During respiration a lot the leaves point towards the surface because the plant doesn't need the light for respiration. However this is more easily seen in moderate to high light tanks. 

A analog light timer costs about $5 for a cheap one. All my tanks use these. Lights turn on and off automatically then. Till I lose on of the pegs lol.


----------



## Trout

Thanks guys, this has been really helpful. I didn't really know what the deal was with lighting. Now I know!


----------



## TheOldSalt

And knowing is half the battle!


----------

