Intense light harmful to "shade plants"?

defdac

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Aquatic plants are classified as "shade plants", and from time to time I hear people saying this or that plant can't tolerate intense light, like say >0.75 watt/liter.

The plants I've often hear are species of Microsorium, Bolbitis and now the last one: Echinodorus.

I don't believe in this. I have a gut feeling that if you provide stable source of nutrients and CO2 you will be able to grow all plants with high growth-rates in insanely high light.

But I have no experience, and if it is true that some plants don't tolerate high light I would like to know a bit more scientifically why that is so?
 

Vladimir Zhurov

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Re: Intense light harmful to "shade plants"?

defdac said:
Aquatic plants are classified as "shade plants", and from time to time I hear people saying this or that plant can't tolerate intense light, like say >0.75 watt/liter.

The plants I've often hear are species of Microsorium, Bolbitis and now the last one: Echinodorus.

I don't believe in this. I have a gut feeling that if you provide stable source of nutrients and CO2 you will be able to grow all plants with high growth-rates in insanely high light.

But I have no experience, and if it is true that some plants don't tolerate high light I would like to know a bit more scientifically why that is so?

I think it is a misinterpretation of situation that would occur if aquarium plants will be growing in their natural environments - many of them (especially species of Echinodorus) will be at least partially or even fully emersed*. Then things like direct sun light and low humidity will likely to do most of them as they are not CAM/C4 plants, do not have thick protective cuticles on their leaves, do not have certain stomata adaptations to retain water.

Fully submersed and with plenty of CO2 provided they should be fine at light levels used in even a "high-light tank" (still very low light in fact if compared to say sun at noon).

This is what I think, may be there are certain exceptions, but it will not be species of Microsorium, Bolbitis and Echinodorus.

Regards.

Vladimir.

* - for example, why is one of the commonly used rotala is called Rotala rotundifolia or literaly round-leafed plant? Because in nature it is a marsh plant growing emersed with round leaves.
 

alexperez

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Jan 24, 2005
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Re: Intense light harmful to "shade plants"?

I recently moved some Narrow Leaf Java Ferns from My 5.8 WPG tank to a small
2.1 WPG tank. I have noticed more growth in 2 weeks in the low light tank than in 2 months in the high light tank. Go Figure?
 

Tom Barr

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Re: Intense light harmful to "shade plants"?

defdac said:
Aquatic plants are classified as "shade plants", and from time to time I hear people saying this or that plant can't tolerate intense light, like say >0.75 watt/liter.

The plants I've often hear are species of Microsorium, Bolbitis and now the last one: Echinodorus.

I don't believe in this. I have a gut feeling that if you provide stable source of nutrients and CO2 you will be able to grow all plants with high growth-rates in insanely high light.

But I have no experience, and if it is true that some plants don't tolerate high light I would like to know a bit more scientifically why that is so?

Your notions are correct.
All submersed aquatic plants are low light weeds.
They have to be to succeed underwater.
The issue really is why do you need insane light levels?

You don't and it's easier to prune and maintain tank with less light and far more stable if you maintain the CO2/nutrients.

Anubias do fine under MH's, but they do well under 1.5 w/gal of FL's also.


Regards,
Tom Barr
 

baruch mor

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Jan 23, 2005
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Re: Intense light harmful to "shade plants"?

i love the use of high light setups. the stlaks always look thick and healthy than low lights setups. i can grow there everything without considering whether i have enough light for this species or not and never saw any problem with "shade plants".
the trick in high light setups is great amount of fert's, a lot of co2 during light hours (close it at night is a must cause im using way to much ) and a lot of w/c.
here is my anubias nana and microsorum under 1.5 watts per liter
ori_142.jpg


ori_141.jpg


Picture_054.jpg


imo - if u can afford it-make your plants happy and always go for high light setups!
 

Tom Barr

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Re: Intense light harmful to "shade plants"?

I'll take some photo's of my non CO2 12 liter(~3.5 gal) tank(I have two of them).

You are going to crap in your pants.
It has 7 w(2w/gal). I'll post in a day or two.
You can also see the cover of the 1st PAM issue, that's a 2.1 w/gal tank.
George Booth's tanks are also 2w/gal or less.

I'm not knocking high light, I'm justs aying you can get truly dense growth and easier maintenance with less light if you wait a bit.

My Gloss in the non CO2 tank grows nicely, not like a damn weed.
It also stays very small.

I use high light to test the limits of plants/algae mainly, otherwise I'll go with a less.

Regards,
Tom Barr