Discus colour change at night?

[tannin]

Over the years, I have noticed different fish change colour into a 'sleep' mode at night when the lights are off. You see it if you turn the lights on for some reason in the middle of the night. Do discus do this too?

The reason I ask, is that one of my discus' body colour seems to go a shade darker just BEFORE the lights go out. If this is his way of saying he is tired, then maybe I should shorten the time my lights are on. The trouble is, morning sun, even through the curtains, seems to have them awake by 8 am, and if I want the lights on until 9 pm, so I can enjoy watching my fish, then that is 13 hours, which I am worried may be too long.

[Also, I say "one" of my discus, as he is the one closest to natural colour, and one of only 2 that show communication/stress bars. The others, with pigeon blood heritage I guess, don't, and so also wouldn't show this darkening of the underlying body colour.]

[dprais1]

yes mine all do. but most seem to get lighter when i first turn the lights on except the pb strains that all pepper-up

[adammak47]

mine usually turn lighter color.

[DiscusKev]

From my experience:

When the light switches on from a dark room, a discus will appear pale and their eyes will often be less vivid (instead of bright red, if red, it will be just orange, there's a name for this colour but I'm tired right now and can't remember it. No big deal though)

It is until the discus get use to the new un-natural lighting, it will revert back to normal colour. This 'colour changing' effect won't be evident through natural lighting (sun rise).

So yes, you can say they go to a 'sleep' mode but I prefer to call it resting mode. Can't remember who said this on SD but Discus more or less rest than sleep since they don't have eye lids. They are however, still aware of their surroundings.

Remember that Pigeon Blood variants don't show communication/stress bar, instead they show peppering. However, good quality PB variants (through selective breeding) show little or no peppering.

[tannin]

Thanks for the replies everyone.

Do you think 13 hours of light is too much, or are they probably used to it by now (I've had them about a month)?