Do fish need light?

[betsonmets12]

Does the light in a non-planted tank need to be on? If so, for how long?

[fishisme]

youse a light, then you can look at the fish... but they will live without, just harder for them to see the food.

[pophead]

I've heard it has something to do with the fish's balance. I'm not sure though.
but why not a light? unless there is lots of outside light you won't be able to see the fish as well.

[graphicdesign_r]

youse a light, then you can look at the fish... but they will live without, just harder for them to see the food.

:rant2:

Bad info. Bad fishisme! Bad!!

Fish need light. People need light. Vegetables need light. Minerals don't need light because they are DEAD.

If you would like your fish to become minerals, then they do not need light.

Most species require day and night in a cycle similar to the wild if they are to remain healthy. There are alot of reasons, but here's the biggies:

It regulates their metabolism
It establishes a sleep/wake cycle
It provides vitamins & nutrients
It extablishes the cycle for beneficial bacteria
It establishes algae which some species eat

The fish who do not need light are deep ocean fish. These fish live at extremely high pressures and if you have a setup for fish that do not need light, you are an aquarium god and I want your setup (I have always wanted some creepy viperfish and glowy hatchetfish for my game room).

[Aqualung]

No, the light doesn't need to be on in an unplanted tank, but it makes it much easier to enjoy the fish.

graphicdesign - I'm wondering where you get your information?

[IceH2O]

You know what happens to fish that have no light?

Their eyes disappear, just like the fish in caves. This happened to my friends fish, it wasn't near any windows and the only light he used was a 60 watt lamp. he likes it dark in his house, says he sees the tv better. it took a long time, probably near a yr but it happened. He wasn't very observant of the fish, guess he was tired of them. Back then neither of us knew about doing water changes, so the only time he saw them was feeding time and I doubt he looked then.

I came to his house one day and looked at the fish and they had no eyes, none zilch. He thought it was cool that he now had cave fish.

[graphicdesign_r]

Aqualung (let me guess, last name Rockbrain :joke: ),

:idea2:

It's common sense that animals who live in a natural environment should have that environment duplicated as closely as possible in captivity for good health... where do you get your info (since it's totally bogus and wrong)?

Please explain to me why fish don't need light? (or better yet go live in a cave for a year with no light and we'll see how healthy you are when you come out... we could make a game of it and have before and after pics). :D

[kveeti]

I think people are getting confused over light (the aquarium light), natural room light, and total darkness. A fish tank in a room with a window that lets in light will be fine, the fish do not need the aquarium light on, they still will get day and night. If the tank is in a dark basement then, yes, the aquarium light will take the place of daytime.

[Aqualung]

The question wasn't whether or not the fish should be kept in a cave, the poster asked whether or not the tank light needs to be left on in an unplanted tank. The answer to that is quite simply, no.

Rockbrain, huh? :troll:

I guess I should get a light for my cannister filter to establish my cycle huh?

[graphicdesign_r]

I'm sorry, I did not realize you were intimately familiar with the setup the original poster has that is being discussed.

The question was "Do fish need light?" (see title of post), not "Is Aqualung available for bad advice and crummy attitude?"

Since you are intimately familiar with their setup, I wonder why this person did not ask you for your advice seeing how you know everything about fish biology and how light affects it. I am guessing maybe they followed your pi$$ poor advice in the past and paid the price.

[Aqualung]

graphic, maybe you should read the posting guidelines.

[fishisme]

WOW WOW... lol got that 1 off 2 a bad start... o well i got it going. just turn the light on at feeding and viewing time the rest of the time i leave off.. sorry for that.

[easy60man]

This is my first post in these forums.

I wanted to find out about 'lighting' for my tank, which has only artificial plants,but 20 fish, in an Aquaone AR850.

after reading this post, i wonder if i have chosen the CORRECT forum for advice.

The original poster asks a simple question only to be answered with stupid, joke type answers.

IS this forum dedicated to fish keeping, or keeping JOKERS???

:mad2:

[blitzen25bm]

you dont need the lights over the tanks. i only have 1 tank with lights all the rest dont have any and they are just lit with natural sunlight and some are kept dim pretty much all the time those tanks are in the garage. theres still enough for them to swim around and know when its night cause they will go to sleep late in the evening.

[Sully]

other than the comment about the cycle for beneficial bacteria it looks like Graphic Designer has it right on (light is critical for vitamin D in fish just like people. D means better disease control). Ambient room light should be enough to do that. Do you need to turn an aquarium light on and off--no, If you have sufficient ambient room light.

Eyes fell off--that is good. The fish evolved right in front of your eyes? Did not even become a generational thing? wish i had been there.

[graphicdesign_r]

This is my first post in these forums.

I wanted to find out about 'lighting' for my tank, which has only artificial plants,but 20 fish, in an Aquaone AR850.

after reading this post, i wonder if i have chosen the CORRECT forum for advice.

The original poster asks a simple question only to be answered with stupid, joke type answers.

IS this forum dedicated to fish keeping, or keeping JOKERS???

:mad2:

Well, a sense of humor helps. Not just here but in all areas of life generally. So "easy60man", my first advice to you? Take it "easy". Your first post doesn't have you starting on the right foot, and the "grumpy old aquarist" forum is a few clicks down the web.

I keep my posting lighthearted because I've learned otherwise the people who take themselves too seriously get bent out of shape and start being snide and offensive (see above), especially when they are wrong and can't back up their argument with facts. That leads to personal attacks, flame wars, complaints to mods... the usual forum politics.

Now on to the real topic. Light.

By stating that fish need light (well maybe not cavefish and those living at the bottom of the ocean, they have ADAPTED to live without it, and are NOT case in point why "all fish don't need light"), I am just trying to say that if your fish come from an environment that has light, they will benefit from a tank that provides light.

Fish tanks are typically not situated in front of windows, where sunlight could provide appropriate ambient light. Also to be taken into consideration is the position of the tank in relation to the sun. My tank faces the west side, and receives little light until late in the day.

All light is not equal. Sunlight provides things that flourescent lights and other forms of residential illumination do not. That is why some lights are more expensive than others. Many tank light systems mimic the spectrum of light afforded by natural sources, and this is desirable.

Your fishtank is a mini ecosystem, complete with biorythyms, microfauna, and organic chemistry. This ecosystem is regulated by natural changes and rythyms governed by (drum roll please) light! Some fish (many actually) will only breed or spawn if the "days" are a certain length. WHY? Because nature has instilled in that species a disposition to do so because their young have a better chance to survive during that time of year.

I have yet to hear a reasonable argument for the "other side" but I'm waiting! And NO, the "I keep my poorly treated fish in an unlit unheated garage and they don't die too much" is not a reasonable argument why fish should be kept in the dark.
:read:
Thanks Sully, good to get another voice of reason here. I'm not sure about the cycling thing, I thought a light schedule was desirable during the cycle, but maybe I am confused about the role it plays? Maybe with all those quick BioSpira cycles the art of stabilizing a tank naturally is obsolete! :) Good, less waiting, more fish watching!

[easy60man]

Well, a sense of humor helps. Not just here but in all areas of life generally. So "easy60man", my first advice to you? Take it "easy". Your first post doesn't have you starting on the right foot, and the "grumpy old aquarist" forum is a few clicks down the web.

I keep my posting lighthearted because I've learned otherwise the people who take themselves too seriously get bent out of shape and start being snide and offensive (see above), especially when they are wrong and can't back up their argument with facts. That leads to personal attacks, flame wars, complaints to mods... the usual forum politics.

[

A straight forward Simple answer, to a straight forward Simple question, is all that we need.

So as you see me or others as "Grumpy old Aquarists" and telling us to "Move on Down" IS personal attacking, snide and offensive. I think you should 'lighten up' and answer simple questions with simple answers. Off Topis forums is the place for snide, grumpy comments.

[mandimoron]

Well, there were a couple of straight-forward simple answers, but then there was disagreement, which created a dialogue. That is the nature of the internet forum, I suppose. It happens a lot around here, as we have many members, all of whom have had a plethora of different experiences in their years of keeping fish. There will always be discussion and debate, and often questions that initially seem very simple may in fact be much more complicated. Personally, I like this kind of atmosphere. But to each his own, right?

[Sully]

easy60man. i too am an old fart. i spend a lot of time on fish boards for some reason--or at least blow by them with regularity. I've been keeping fish since late 60's. doing boards for about 4 years. it is a different world on boards.

i am regarded as a reasonable person on a couple others that i frequent. rarely saing anything out of line (actually am a mod on one). but, some issues, for whatever reason 9probably because they are issues i happen to have an opinion about) i can be perceived as a "pain in the ***". that is never my intent. usually it is simply to generate dialog. that way maybe i can get someone to agree with me, change my thinking, or agree to disagree. it is always well intentioned.

i guess the key is to simply look for the "information" you are after and ignore the stuff that trips your trigger. unless it is a trollish post the other individual rarely means to be abrasive or insulting.

the graphic design guy probably gets carried away on his G5 playing in photoshop to create really cool avatars and never thinks he is being rude. probably thinks he is just being helpful. The web personalities of some people can annoy you just like the personalities you encounter face to face. they do not usually mean to--sometimes it just happens (ask daveedka about that hard headed, pain in the ***, misguided thinker that calls himself sully--lol).

sometimes it is also about what the other person thinks they need to provide a cogent answer that is helpful to you.

[RockabillyChick]

don't know if anyone mentioned this already, but fish need sunlight to produce vitamin d, which is a vital nutrient. in fact, every living thing needs sunlight to produce this vitamin. they also will not eat if it is dark. so yes, they do need a light.

[Sully]

ambient room light in most instances is enough light for the fish to receive appropriate nutrients. (yes there are some exceptions we can all think about and create for sake of arguement).

tank lights are usually flourescents--not the same as the sun. the fish do not get what they need from "electrical lighting". they need at least indirect sun light. Light is typically the last issue causing problems. think about our own issues with vitamin d in the winter months--simple distance from sun in winter stops us from getting as much as we need. plenty of "sun light". just not close enough. many similarities with fish.

The lights that come with tanks are really so hobbyists can enjoy the fish. not really doing anything for the fish themselves.

[RockabillyChick]

its not the source of the light that matters, its the spectrum. why do you think plants can grow under flourecent lights? its not sunlight, but they still grow happily. i use a flourecent daylight bulb over my plants since my windows are all east facing and about 4 feet away from a 2 story building.

[Sully]

Yes. You are right. I tried to avoid a long answer in the middle of the night.

The light required to do any good at all in a fish tank is “full spectrum light”. Vitamin D is one of the key vitamins received as a consequence of the middle range of ultra violet radiation.

The bulbs frequently utilized by hobbyists, without planted tanks are, however, the common fluorescent tube. These supply little if any of the mid range ultra violets essential fro the generation of D3. “Day light” tubes have a better balance of the various bands of the light spectrum. If the hobbyist feels the need to supplement ambient light then he/she would want to use bulbs with a CRI>88 (CRI=Color Rendering Index). They are most like mid day sun. Basically the bulbs should be at least 5,000 K. 6500 K is maybe better (this range is often used for judging accuracy of color replication in the graphic arts world).

The only statements I ever found referencing light and fish say that fish require a minimum of 6 hours a day of sun like light. At the same time some of the sites state that “5 watts per gallon” is a minimum required to facilitate the benefit of “day light”. That would be a lot of light (I periodically plug that level of light in for a planted tank—but rarely leave it at that intensity for long (only when I kick up CO2 and fertilizers to generate a bit more rapid growth).

I cannot say that I cannot say with any scientific certainty what the minimum time required, or minimum watts per gallon required are. I can use experience dating back over 25 years when I started keeping fish. I can also make use of anecdotal information from hobbyists I have known and trusted as well as hobbyists I have met online. And, I can go back into history, when royalty kept tanks without heat, light or the type of filtration we utilize.

I have kept tanks for many years that had no supplemental light. They got the ambient room light during the day (or useless fluorescent and incandescent light). The life spans and the fecundity of the fish were no different than of fish kept in “lighted” tanks.
Breeding activity occurred. Growth occurred. And the fish lived as long (or longer) than the “average number of years bandied about as what we should expect.

Maybe this should be a topic for doctoral research as well. Why don’t more people do more “scientific” research into fish? Until they do, however, I guess the best I can go by, in an instance like this, is what has worked or not worked. I guess it is taking advantage of the “body of knowledge”. Without really knowing its source.

[mandimoron]

Maybe this should be a topic for doctoral research as well. Why don’t more people do more “scientific” research into fish?

Haha, funny you should say that. Ever since I got into this fershluggner hobby, I've been trying to cook up ways I can do my thesis on aquarium fish so that I'll have an excuse to buy lots of tanks and spend all my time fawning over their inhabitants. :dive2:

[Slappy*McFish]

Personally, I'd give the fish at least 8 hrs of light every day. Put the lights on a timer and never have to worry about it.

[TKOS]

Fish, unlike mammals, birds and reptiles, do not respond to sunlight and rely on vitamin D found in phytoplankton and other fish. Salmon must feed on phytoplankton and fish in order to obtain and store significant vitamin D in their fat, flesh, skin, and organs.

Ahhh, don't compare fish to humans as far as Vitamin D is concerned.

As for a daily cycle being a good thing. Well since the fish we keep are from relatively shallow waters then they are used to some form of light, though what sort of level would be debatable since water filters light and what ever is in the water can filter it more.

Will fish loose their eyes without light? No, but poor living conditions could make that happen.

Oh and farm raised fish is a poor source of Vitamin D for people. This is due to diet. Wild caught fish is still a great source of vitamin D. Yet, both get light.

Lots of ponder. And so easy to do without personal attacks. Hmmmmmmmm

[Aqualung]

Thanks TKOS, for a very thoughtful post!

What you have just explained is what I was getting at before the personal attacks started. I started to type a lengthy reply (which wouldn't have been as well stated as yours by the way), but I was a bit upset with the tone of certain posts and wasn't clear-headed at the time.

[TKOS]

It is easy to get upset when the person you are talking to (writing to) isn't there, but eventually the brain will kick in and remind us what we are here for. Perhaps Vit D helps with that? More sunlight for me!!!

[Roan Art]

The RML (Rainbow Mailing List) advocates keeping rainbows near windows so that they can get at least an hour of sunight a day directly on the tank.

Apparently, and I've yet to test this claim because I do not have enough window access, bows like to bask in the sun and will swim in only the sunlit areas of the tank during that period of the day.

Quite a few of them do this and I believe them.

Also, many Australian keepers pond their rainbows and have reported they are healthier, bigger and more long-lived.

Food for thought.

Roan