Should I turn my tank light off?? -

members chatting

Welcome to the

Find the answers to your fish problems or questions here on by using the search box below:

Go Back > Freshwater > Beginner Freshwater

Beginner Freshwater You got questions? This is where to post them.

Thread Tools Display Modes
Old 03-12-2011, 06:13 PM   #1
Junior Member
Join Date: Mar 2011
Age: 25
Posts: 10
Default Should I turn my tank light off??

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?
danibu is offline   Reply With Quote
Sponsored Links
Old 03-12-2011, 07:30 PM   #2
Fishy Member
serpa_man's Avatar
Join Date: Mar 2011
Location: Port Angeles, WA
Age: 24
Posts: 49

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.
serpa_man is offline   Reply With Quote
Old 03-12-2011, 07:39 PM   #3
Discus Keeper
snyderguy's Avatar
Join Date: Feb 2010
Location: Michigan
Age: 25
Posts: 1,396

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.
"The beauty is within the aquarium itself"
snyderguy is offline   Reply With Quote
Old 03-14-2011, 09:03 AM   #4
Junior Member
Scotty00's Avatar
Join Date: Mar 2011
Age: 28
Posts: 1

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.

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.
fish tanks
Scotty00 is offline   Reply With Quote
Old 03-14-2011, 02:23 PM   #5
Senior Member
Join Date: Jan 2011
Location: leesville LA.
Age: 29
Posts: 543

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.
chronoboy is offline   Reply With Quote
Old 03-14-2011, 02:53 PM   #6
Mr. fish
Senior Member
Mr. fish's Avatar
Join Date: Mar 2011
Posts: 582

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
Mr. fish is offline   Reply With Quote
Old 03-14-2011, 08:07 PM   #7
girth vader
Hey Now!
girth vader's Avatar
Join Date: Apr 2006
Age: 40
Posts: 673

In short, turn the lights off for 10 hrs/day.
I have a tank!!! A nice one too!
girth vader is offline   Reply With Quote
Old 03-15-2011, 08:32 AM   #8
Ghost Knife
Permanent Fishaholic
Ghost Knife's Avatar
Join Date: Mar 2008
Location: Mississippi
Age: 33
Posts: 1,623

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.
125 Gallon Semi-Aggressive
2 African Brown Knives
4 Albino Cories
1 Black Ghost Knife
2 Blue Gouramis
1 Bristlenose Pleco
4 Bronze Cories
1 Brown Spotted Pleco
1 Common Pleco
7 Emerald Cories
8 Gold Barbs
3 Julii Cories
1 Lake Malawi Syno
4 Peppered Cories
6 Red-Tailed Tinfoil Barbs
5 Rosy Barbs
5 Silver Dollars

20 Gallon Community
5 Albino Cories
2 Ghost Shrimp
7 Glowlight Tetras
1 Common Pleco
3 Yellow Guppies
6 Zebra Danios

Ghost Knife is offline   Reply With Quote
Old 03-16-2011, 02:07 AM   #9
Darth Ichthyos

TheOldSalt's Avatar
Join Date: Jan 2005
Posts: 8,945

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.
TheOldSalt is offline   Reply With Quote
Old 03-27-2011, 11:22 AM   #10
SGT Z's Avatar
Join Date: Jul 2010
Posts: 128

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.
SGT Z is offline   Reply With Quote
Old 03-27-2011, 11:31 AM   #11
ronmarsh99's Avatar
Join Date: Feb 2011
Location: Toronto
Age: 45
Posts: 51

yes it's bad as fish r like people they need to sleep plus you will be fighting green algae.
ronmarsh99 is offline   Reply With Quote
Old 03-27-2011, 12:21 PM   #12
Senior Member
Mikaila31's Avatar
Join Date: Nov 2009
Location: Hudson, WI
Age: 25
Posts: 743

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.
*You never know what lies below.....*
Mikaila31 is offline   Reply With Quote
Old 03-28-2011, 01:30 AM   #13
Senior Member
Trout's Avatar
Join Date: Mar 2011
Location: Sunnyside, WA
Age: 23
Posts: 251

Thanks guys, this has been really helpful. I didn't really know what the deal was with lighting. Now I know!
Trout is offline   Reply With Quote
Old 03-28-2011, 09:01 AM   #14
Darth Ichthyos

TheOldSalt's Avatar
Join Date: Jan 2005
Posts: 8,945

And knowing is half the battle!
TheOldSalt is offline   Reply With Quote
Sponsored Links


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Quick turn for the worse AndrealvsDennis Beginner Freshwater 10 01-02-2011 10:40 AM
My turn to share TheOtherNewGuy User Journals 17 06-22-2009 09:45 PM
why do goldfish turn white? igauresh Goldfish, Koi, and Ponds 2 11-28-2006 12:30 PM
How much $ to turn a FOWLR into a Reef... Fishnewb1 Reef 24 07-13-2006 02:57 PM
Glolights turn white Sebastian-Crab Diseases 0 03-19-2006 08:32 AM