# How dark should be the "dark" period?



## aviel (Sep 12, 2004)

Hi,

We usually provide our plants with 10-12 light period for photosynthesis.

But what about the other 12-14 hours of darkness? how dark could they be?

During the hot summer days I was turning on the lights during the night and in the morning/noon time the tank lights were off but the tank got tons of indirect sun light penetrating through the very big window in my living room. I noticed that plants weren't during very good and would like to understand if it was more of a heat issue (29-30C).

I think plants need darkness in order to respire but this ends my understanding of this.

Could anyone please educate me a little more?

Aviel.


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## aviel (Sep 12, 2004)

Hi again,

There must be someone that can help me with my question here.

Right?

Aviel.


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## Sir_BlackhOle (Jan 25, 2004)

I dont know...but I always try to keep my tank dark for around 12 hours or so. I've covered tanks with a towel to keep em dark.


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## Adam (Oct 19, 2004)

Well I dont know for certain but I suppose a guess is better then nothing at this point.

I would assume that as long as the room is "dark" regardless if there is some ambient light in the room it should be fine. If you think about it the night time is never completely black unless you are no where near a street lamp on a new moon. And it can be fairly bright on a full moon.

I would just try to make sure that all the lights, are off in the room that you can, but light coming in from another room or a night light etc shouldnt affect the plants.


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## Hanzo (Mar 9, 2004)

I would think that the only thing that matters here is that the plants can clearly tell day from night? I have a small 9W bluelight running over my tank all night to keep my hatchet fish from going crazy when the lights go out, and I have not discovered any negativ side effect to this. In fact I would say it might have a upside even. Before this my plants would start leaning towards the window when the sun got up, and then use some time to adjust itself to the light in the tank when that finally lit up a coulpe of hours later.


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## HeyPK (Jan 23, 2004)

The only plants I have ever seen harmed by not having a dark period are in the genus Hygrophila. If these plants are producing distorted leaves, then they are getting an insufficent dark period.


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