Why Do Fish Need Darkness At Night?

Is it like important for their health or something?

 

I think so. In the wild they have dark at night and I guess they have natural instincts to rest at night- or whenever it's late and the tank is dark. Also it uses less power to turn your light off at night.

 

Fish need rest just like people do, whether they actually need nighttime is uncertain and debatable.

 

Light makes algae grow faster, too. I've heard that leaving your lights on 24/7 can turn your tank green pretty quickly.

 

Light makes algae grow faster, too. I've heard that leaving your lights on 24/7 can turn your tank green pretty quickly.

... so, I need to leave it on if I want to get things ready for my pleco babies
I turn mine off because my husband complains about the light from the LEDs. Soon I will also have nocturnal species, which will need at least the illusion of night. Tried leaving the blue light on, but hubby still thought it was too distracting :/ So for now, they get true night.

 

People wouldn't do well in constant bright light either

 

I can't sleep when there's some sort of light on. Even a night light bugs the heck outta me. I like it pitch black, so I do the same to my fish. In the am when sunlight comes through my window, my fish somehow know it's breakfast time. They're all energetic and zooming all over the place. Tells me they like it dark at night too

 

People wouldn't do well in constant bright light either

That's why they make those black masks for sleeping. I went years without sleeping in what most would consider a "properly" dark room. Ships at sea don't sleep. You adjust, learn to nap/sleep when and wherever you can.
I suspect that fish are the same. I've watched my tank a little bit and it seems that the entire thing will be a madhouse at times and others they all seem to be taking a timeout, as though they've all agreed that it was nap time.

 

Quite simply, fish sleep. Some still move around if they need water flow across their gills but they do infact sleep. Most fish (except sharks) don't have eyelids so darkening the tank is a benefit. They are not always on a typical circadian rhythm but most are about during the day. Some drift on the bottom like cichlids but they all slow down and sleep.

 

would it still be considered darkness to the fish if the tank light is turned off but there's still some light in the room? me and boyfriends sleep schedule is not regular and he refuses to be in the dark for the fish. ive been wondering about this for awhile

 

... so, I need to leave it on if I want to get things ready for my pleco babies
I turn mine off because my husband complains about the light from the LEDs. Soon I will also have nocturnal species, which will need at least the illusion of night. Tried leaving the blue light on, but hubby still thought it was too distracting :/ So for now, they get true night.

You will have to leave a lot of fish flakes and the light on 24/7. It will take a few days. I suggest putting them in a mature tank because it has little critters we can't see ourselves that they eat.

 

would it still be considered darkness to the fish if the tank light is turned off but there's still some light in the room? me and boyfriends sleep schedule is not regular and he refuses to be in the dark for the fish. ive been wondering about this for awhile

That should be fine. After all, they're used to moonlight and other indirect sources of light. As long as it's dimmer at night than during the day, they'll think it's night.

 

Also certain nocturnal species need darkness for their more active periods.

 

That's why they make those black masks for sleeping. I went years without sleeping in what most would consider a "properly" dark room. Ships at sea don't sleep. You adjust, learn to nap/sleep when and wherever you can.
I suspect that fish are the same. I've watched my tank a little bit and it seems that the entire thing will be a madhouse at times and others they all seem to be taking a timeout, as though they've all agreed that it was nap time.

I was thinking of times napping in hospital hallways. If I was thinking straight, I nabbed a mask to put over my eyes. If not (which was usually), an arm or a hoodie does as well...

 

would it still be considered darkness to the fish if the tank light is turned off but there's still some light in the room? me and boyfriends sleep schedule is not regular and he refuses to be in the dark for the fish. ive been wondering about this for awhile

So what you're talking about is indirect light. Realistically just securing the tank light should be fine. Even with smaller tanks the light from a room is insufficient to penetrate very deeply into the tank as far as actual luminescence (brightness). So you can leave the other lights on and they will be sleepy.

I was thinking of times napping in hospital hallways. If I was thinking straight, I nabbed a mask to put over my eyes. If not (which was usually), an arm or a hoodie does as well...

We don't get a lot of good sleep underway in the Navy. You always have something going on, lights, machinery operating and what not.

 

We don't get a lot of good sleep underway in the Navy. You always have something going on, lights, machinery operating and what not.

Oh come on man, I've seen the Chiefs berthing compartment. Luxury hotels are envious.

 

Oh come on man, I've seen the Chiefs berthing compartment. Luxury hotels are envious.

I'm a Submariner

 

I'm a Submariner

I figured as much being in Groton. Special kind of crazy. Glad you guys are out there. Saw a boomer boat surface in the middle of the Med once. That was... odd. Only thing I could figure was they had been to La Maddalena and were doing some testing. Was definitely a US boat.

 

One thing no one else has addressed about turning the lights off for fish, that is aggression. With the lights off the aggression of fish go way down. I always feed my bottom feeding fish at night right before I turn off the lights, because that is when they are more active at night looking for something to eat. The bottom feeders in my tank stay hidden most of the time during the day and when the tank lights are on.

 

One thing no one else has addressed about turning the lights off for fish, that is aggression. With the lights off the aggression of fish go way down. I always feed my bottom feeding fish at night right before I turn off the lights, because that is when they are more active at night looking for something to eat. The bottom feeders in my tank stay hidden most of the time during the day and when the tank lights are on.

Hmmm... so, it's also important to keep the lights ON if you have something like a catfish or crayfish which might eat it's tank mates in the dark...although that will probably happen eventually, lights or no

 

Hmmm... so, it's also important to keep the lights ON if you have something like a catfish or crayfish which might eat it's tank mates in the dark...although that will probably happen eventually, lights or no

You must live one house down from me on Loony Lane...........ha ha j/k...

 

Imagine yourself sleeping while the lights are turned on. Unless you want to see sleepless zombie fishies

 

OK... so the tank in my son's room and the ones in my office are all on timers which go off at 8:30pm. That used to be just before it actually got dark. My son's betta's light actually went off while I was doing the water change tonight, so I hurried up and then left him (and my son) to go to sleep, then put the stuff away in my office and shut doors, etc. By the time I got out to the new tank in the living room again, it was 9pm, and dark outside. So I decided it was probably their bedtime too, and turned off their LED.

PANDEMONIUM. The endler panicked, swimming into the glass, on the site that the hall light was shining in, diving and flashing and just going crazy. So I turned on their blue light...instant calm. Apparently they don't want to be in the dark right now O_O
Half the boys in there I introduced tonight...going to give them some more time to settle in...

 

All fish need sleep and it's important to maintain a day/night schedule for them. Imagine the sun never setting and always up

 

In the med it was a ssgn. Same hull as a Thull.

I know you guys have probably heard this so much your tired of it.
But I will say it again anyway, "Thank you for your service."

 

I know you guys have probably heard this so much your tired of it.
But I will say it again anyway, "Thank you for your service."

I never get tired of it. You are welcome and thank you for your support.

 

They need it because Stevie says so

 

Not familiar with Thull. This was ~'81. I was still SMSA, older Vietnam era guys are the ones who said it was a boomer.

Ohhh yeah probably lafayette or madison class. Boomer. T-hull means trident which is the current "boomer". Usually only salty guys like me and you call em boomers now. I'm a fast boat and boomer guy. Half my career on one class the other half on the other.

 

Please don’t derail this thread any further with off topic chat, if you want to continue your side discussion then start a new thread

 

I have my fish in a living room where we commonly stay up very late, sometimes till 3 in the morning. I have my fishes' lights on a timer that comes on at about 9:30 in the morning and goes off at about 9:30 at night. I actually cover my fish tank with a scarf if we're in the room doing things up past 10 or 11 so the ambient light doesn't keep them from resting. I got the idea because I also cover up my birds at night so that the light doesn't distract them from resting either!

 

I never get tired of it. You are welcome and thank you for your support.

Thank you for your service. You are greatly appreciated

 

I never get tired of it. You are welcome and thank you for your support.

I love talking to and see people who serve in the military because they put their lives on the line just for America.

 

Again, further to post #31 please don’t continue to derail this thread, further posts not on topic will be removed

 

Again, further to post #31 please don’t continue to derail this thread, further posts not on topic will be removed

So we can't say thank you to people who have served in the military? I don't think you should be saying that. IMO I will always say thanks to a military person as they have gone through a lot.
edit: I will be talking to jdhef about that because they deserve to be thanked. Esp if the OP doesn't mind it.

 

I have no problem thanking the military, they’re very much appreciated but do it on a separate thread as asked in previous post, thanks.

 

Fish sleep... Just like people do. They just don't have eyelids so it looks like they're awake.

 

Fish sleep... Just like people do. They just don't have eyelids so it looks like they're awake.

I want a pair of glasses with open eyeballs painted on them so I can sleep and still look like I'm awake.

 

I want a pair of glasses with open eyeballs painted on them so I can sleep and still look like I'm awake.

got them!

 

So bottom line is that fish do infact sleep, its a weird kinda sleep like cats but they do sleep. Some fish like carp actually go into an almost hibernative state in winter depending on where you're at in the world and environmental effects. Indirect light from your room lights is not gonna impact them. I keep my tanks on a timer and they get light 8 hours a day (also nice on ye olde electric bill). Even in the dark though they could be out n about doing their aquatic mischief.

 

would it still be considered darkness to the fish if the tank light is turned off but there's still some light in the room?

So I turned on their blue light...instant calm.

My lights have a dark all blue light setting, is this like a night setting? Can I just turn that on at night instead of just turning everything off?

 

that's called "moonlight" it looks cool and can be moonlighty (its a word) but you are still powering your light and depending on intensity you can still be feeding the photosynthetic process for algae

 

I remember hearing about some research a long, long time ago that showed that most fish need a period of reduced light/darkness to replenish certain proteins or enzymes in their optical systems. It may have only referenced certain types of fish, but I can't find an online reference, as this may predate the internet. You would be surprised at how much knowledge existed before the internet, and how much of it has been forgotten because of the internet.

 

All fish need sleep and it's important to maintain a day/night schedule for them. Imagine the sun never setting and always up

I don't need to imagine it Growing up in Northern Norway there were two months in summer with 24 hrs sun, and 2 months in winter with no sun at all. And it really messes up your inner clock so you want to be awake all the time or sleep all the time, or at least sleep at the wrong times in the day.

I live further south now, so there's only a short period in summer when it's dark for just a couple of hours. But after a while I still decided to close the curtains in my living room when I wasn't at home, because my tank turned green and cyano started growing. This way I also have the lights turn on later in the day and turn off later in the evening so that I shift their daytime towards when I'm at home. I see a big difference in the evening after the lights go out. The tetras are most of the time just floating still, moving slightly to keep in place, and my bristlenose is swimming around all over the place eating. So I definitely think it's good for them to have this pause with the lights off.

 

For the same reasons you do:

1. So they can sleep well, which allows their physiological, neurological and cell regeneration systems to reset and "recharge." (Yes, fish do need sleep.)

2. To keep their circadian rhythms entrained properly, which allows all of the systems mentioned in number 1 to be coordinated in their activities. Poor health results from lack of proper entrainment, frequently to the point of death.

Light is the primary entrainment trigger in vertebrates.

Do your fish a favor -- buy a timer and put it on your tank. They will thank you for it with longer, healthier lives.

 

If I have a fish die, it always happens when the lights are off, so I've become superstitions about the moonlight. My cories are a lot less active with the moonlight, so my guess is that's good enough night for them

 

If you’re still worried about fish being kept up even with the tank light off, you can cover your tank with a sheet/pillowcase. I do this for all my tanks because we tend to stay up late or forget to turn out the lights.

 

My Eel is active at night. Swimming around looking for left overs. Its just better to keep things natural. That being said you can keep them on past a certain time if needed.

 

Look into non24. It all has to do with cicardian rhythms and the disorders that stem from cicardian disorders.

 

I think i’d go a little crazy without dark periods. I am also curious how it affects fish. they do not have eyelids so wouldn’t be able to experience darkness unless the environment allowed it.

My timer has been janky lately. I work nights, and came home at 4 or 5 am to realize one of my tank lights had been on all night. it didn’t seem to negatively impact the fish but I still felt badly.

 

Please don’t derail this thread any further with off topic chat, if you want to continue your side discussion then start a new thread

Did you merge like 2 or 3 threads together?? I don't remember saying any of this in this thread.