My Fish Are Scared Of The Dark.

Michelleuk · Oct 25, 2008

Hi

When ever the light goes off in the tank or when the light is off, my fish are very jumpy. They dart around and jump out the water (luckly I have a lid).

Once one of my swordtails was darting around and jumped on the outlet filter pipe. His head was out of the water so I pull the tube of the glass so he could fall back in the water.

They are very jumpy only when the light is off. Sometimes they go around in circles but they are fine in the morning.

Anyone else have this situation in their tank? Any ideas what causes it? Or how to prevent them getting so scared?

THANKS

Truck · Oct 25, 2008

they wont be scared. its instinct. in the wild when its dark they are likely to be more vigilant, as predators hunt at this time. its just instinct

chesterscot · Oct 25, 2008

have to agree fish are more jumpy after lights out if you make sudden movements and stuff its just the way they are although mine dont jump out the water lol
regards scot

guppy_man · Oct 25, 2008

Its because they have a light on for 8 or so hours aday then suddenly in asecond theres no light, they are obviously going to get startled.
Some people buy light dimmers which simulate light conditions in the wild. The light gradualy dims until their completely off which is alot better for the fish.

I have 2 tubes in my tank, both 15W but different brightness, i firstly turn the brighter tube off, and then 5-10 mins later turn the other off.

tenohfive · Oct 25, 2008

As stated above, its nothing to do with how light or dark it is - its a rapid change.

When someone turns on the lights when you're in a dark room, you blink. Fish don't have eyelids and can't do anything to control the amount of light hitting their eyeballs, so its painful.

As stated - you can go down the dimmer route, or what I do is turn the room lights on before I turn the tank lights off, then turn the tank lighting off, give it a few minutes and turn the room lights off. Its a less abrupt transition than from bright light to complete darkness. I do the same when switching tank lights on, just the other way round.