# Overdosing macros turning red plants green?



## GreenGrow (3 Dec 2013)

Hi there everyone! 

I've recently had a set up which had an array of red and pinky plants but gradually they lost their vivid colour and blended into a green colour. I've done of reading and from what I've read the association that people make with red colours are high light and high co2 with some extra iron. I was running an exceptionally high light set up and because of not having introduced any life stock was tripling the necessary co2. I was also flooding the tank with ferts...perhaps x4 the recommended amount to ensure there weren't any deficiencies. 

Could this be the loss of my red growth as I've noticed that knocking back the macros on my other nano has really brought out the red in my mini bonsia? 

If anyone has any experience with this id be grateful to hear it!

Thanks


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## three-fingers (3 Dec 2013)

If you reduced the light, that will be why they are greener IMO. From my understanding, red colours in plants are from pigments called carotenoids that plants produce in response to very high light conditions, as a protection UV . Red pigments are still used for photosynthesis as well, just use different wavelengths.  Red pigments aren't as efficient as green pigments for photosynthesis in most daylight, but this doesn't matter for the plant if it's in such a high light environment that it's having to protect it self from UV underwater!

Many plants in the aquarium produce brown/red tinted leaves near the waters surface where light is strongest, under 4 t5 tubes, even _Egeria densa _has some pretty shades of brown/red at its growing tips.

Personally I don't think what pigments a plant produces has anything to do with nutrients, besides showing symptoms of deficiency.  It's the light that's important, although of course there are many red plants that will do well and stay dark red under low light, red tiger lotus is one I like.


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## Michael W (3 Dec 2013)

I agree with three-fingers, the red pigment is basically our equivalent of having a tan to protect us from the sunlight.


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## GreenGrow (3 Dec 2013)

Ah I see. How does the colour fluctuate in my nano if all the other variables are constant and the only changing factor is the nutrients?

Is the plant more capable to handle its "sun tan" of there are boat loads of ferts?


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## tim (3 Dec 2013)

Lack of nitrogen can also produce red colouration I believe, will affect plant health long term though.


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## three-fingers (3 Dec 2013)

edmills said:


> Ah I see. How does the colour fluctuate in my nano if all the other variables are constant and the only changing factor is the nutrients?
> 
> Is the plant more capable to handle its "sun tan" of there are boat loads of ferts?


I thought you changed the intensity of the light, not just the nutrients? ("I was running an exceptionally high light set up") . Even if not, there are *loads* of potential reasons, as always with aquariums, too many variables to totally account for!

Could be that the plants are more healthy, or less healthy overall due to some interaction with beneficial bacteria or fungi in the substrate, the bacteria or fungi could have in turn been affected by reducing fertilisers, as maybe the levels of one particular element are now just below toxic levels for that particular species of microorganism. Could be that the temperature is different at some point during the day and this favours a one species of bacteria over another. Could just be that the plants have just taken their time to adapt their pigments to the colour temperature and intensity of your bulbs, because other factors were previously hindering this adaptation. All just random guesses, but there's no great mystery, aquariums are just very complex and varied systems!

But, no, if nutrients aren't limited already, then boatloads of extra ferts wont help a plant in any way if it's being blasted by damaging wavelengths of UV light.

Nitrogen deficiency would lead to there being less chlorophyll in the leaves, simply allowing red and yellow pigments to show through instead, like when trees lose the chlorophyll from their leaves in autumn. However, it doesn't actually stimulate them to produce red pigments.

Maybe since ramping your ferts down they look less green due to a very, very slight deficiency. Just depends on the plant, some species are redder than others in given conditions, some are maybe less efficient at up-taking nutrients at lower concentrations, some are more dependant on an established root mass, ect...

TL;DR: variables!


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