# Do Plants Absorb Nutrients When Lights Are Off?



## shrimpletess (Jun 1, 2014)

> Do Plants Absorb Nutrients When Lights Are Off?


 Yes, they do 24/7 regardless of light being present or not.


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## OVT (Nov 29, 2011)

shrimpletess said:


> Yes, they do 24/7 regardless of light being present or not.


Could you please provide more details / references?
I do not believe that statement is correct. Thanks.

v3


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## shrimpletess (Jun 1, 2014)

OVT said:


> Could you please provide more details / references?
> I do not believe that statement is correct. Thanks.
> 
> v3


 Here for example:

http://ir.ihb.ac.cn/bitstream/34200...ersed macrophyte Myriophyllum spicatum L..pdf


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## marle (Jun 16, 2007)

shrimpletess said:


> Yes, they do 24/7 regardless of light being present or not.


what are the type of nutrients plants use when the lights are off aka non photoperiod? 

I definitely know oxygen is needed. What else?


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## Positron (Jul 22, 2013)

Plants sometimes have no choice but to uptake things during the night. It all works with passive diffusion. At night a plant tries to slow this process because it's not using carbon. It does this by ionic balance across cell membranes. However, some amount of things will still be used like all the macros to build amino acids and proteins.


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## shrimpletess (Jun 1, 2014)

marle said:


> what are the type of nutrients plants use when the lights are off aka non photoperiod?
> 
> I definitely know oxygen is needed. What else?


I would ensure that essential micro and macro nutrients are present at any time in the tank and any of them does not get to zero, whatever dosing method one uses.

At what rate the uptake is at night compared to during the day probably depends on too many variables, type of plants, etc...So it is impossible for me to answer such a question. On the previous article I posted there are graphs of nutrient uptake of Ca, Mg, PO4 and K at ligtht time vs dark.

Also, some plants may not uptake nitrate as nitrogen at night but will still uptake ammonium as their nitrogen source.


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## Zapins (Jan 7, 2006)

For background information and educational completeness: 



Zapins said:


> Here is some information you might want to read if you are interested in knowing more about nutrient uptake:
> 
> Summary
> 
> ...


*From*: http://www.plantedtank.net/forums/showthread.php?t=490681&highlight=fert+dissipation+ei+dosing​
Practically speaking:

While plants have certain times of the day and night where uptake of a particular nutrient is elevated you should not try to dose that nutrient at that time. As shrimpletess mentioned you should have all the nutrients in the water 24/7 to ensure the plants do not become deficient. Let the plants choose when they want to uptake nutrients.


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