Do light affect the life/health of fish?

  • We are currently upgrading MFK. thanks! -neo

mshill90

Feeder Fish
MFK Member
Nov 4, 2009
3,179
3
0
Mechanicsburg, PA
While on another thread, someone mentioned that they don't have a light on their pleco tank.

It made us both wonder whether this would through the life cycle off. As there is no light, it can't determine night from day.

I know my pleco is active and eats during the day when the lights are on, and he sits on the bottom in his log when they are off.

Would not keeping a light on the tank have any negative affects on the daily cycle of how a fish lives and acts?
 
BlackShark11k;3892409; said:
these fish get little to no daylight in the wild, lack of lighting will probably not affect them much.

But at times they do get some light. Would cutting off light all together affect things?

And What if there are other fish housed with them? How will they be affected?
 
it might change their color im not sure for plecos but I know if you leave a goldfish in a dark room it will eventually turn white
 
Deep Blue Sea;3892427; said:
it might change their color im not sure for plecos but I know if you leave a goldfish in a dark room it will eventually turn white

That is absolutely NOT true.
 
mshill90;3892404; said:
While on another thread, someone mentioned that they don't have a light on their pleco tank.

It made us both wonder whether this would through the life cycle off. As there is no light, it can't determine night from day.

I know my pleco is active and eats during the day when the lights are on, and he sits on the bottom in his log when they are off.

Would not keeping a light on the tank have any negative affects on the daily cycle of how a fish lives and acts?

Almost certainly.. Pleco's are nocturnal eaters..

However.. In terms of how a fish lives and acts.. It will learn that lights means food or stress.. A fish will learn to adapt to it.. but lights on TOO often is not a good idea...

A tank with light on for a good amount of time will just be screwing up the tank's time cycle... I'm a believer that lights in a tank is only meant for looking at your fish when you want to see it... NOT for the fish to "getting sunshine or enjoying the light".. With that said.. you can have a light in your tank.. I always like to see my tanks at night and do filming..
 
mshill90;3892423; said:
But at times they do get some light. Would cutting off light all together affect things?

And What if there are other fish housed with them? How will they be affected?

and unless you have your tank in a room with no windows they'll get some light in your tank. ;)
 
BlackShark11k;3892458; said:
and unless you have your tank in a room with no windows they'll get some light in your tank. ;)

My tank is in a room with windows, but because it is winter we keep them covered with curtains, so they get NO light.

My tank is boring and lifeless with no lights. Everyone is on the bottom not even moving, and you can't see them because it is so dark.

I would assume there is some benefit to the light. IF you use the right lighting.
 
Deep Blue Sea;3892427; said:
it might change their color im not sure for plecos but I know if you leave a goldfish in a dark room it will eventually turn white

If left in the dark for a period of time, a goldfish will turn almost gray. Goldfish have pigment production in response to light, which is almost like our tanning in the sun. Fish have cells called chromatophores that produce pigments which reflects light, and gives coloration. The color of a goldfish is determined by which pigments are in the cells, how many pigments molecules there are, and whether the pigment is grouped inside the cell or is spaced throughout the cytoplasm. So if a goldfish is kept in the dark it will appear lighter in the morning, and over a long period of time will lose its color.
 
MonsterFishKeepers.com