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Rotala changes colour daily.....

Sammy Islam

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Joined
12 Mar 2019
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692
Location
Hertfordshire
This is probably normal, but my rotala are really pale for the first half of the photo-period and then colour up for the rest. Is that because they are "waking up" still?
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Quite surprising that difference Sammy! From what I have read plants colour up in response to light intensity (ignoring low nitrates which is kind of related). But I didn’t know that could happen within the space of a single photo period.

At what point in the cycle do you dose ferts?
 
Quite surprising that difference Sammy! From what I have read plants colour up in response to light intensity (ignoring low nitrates which is kind of related). But I didn’t know that could happen within the space of a single photo period.

At what point in the cycle do you dose ferts?
That's why i'm so confused, the colour change is very noticeable and i just put it down to "waking up".

Is low nitrates even possible with very hard water and EI dosing? My tapwater contains on average 30ppm, and i also dose 20ppm NO3 per week.

I have been daily dosing EI for nearly 2months now, after i read that thread, did you start it? I dose macros 3hours before lights on, and micros 10mins before lights on. Everything is going well to be fair, everything apart from s.repens grows perfectly, maybe not with as much colour as i would like, but things look decent towards the end of photoperiod
 
Low nitrate is possible with hard water - my tap water is hard but nitrates are around 5ppm, but I figured you were on EI, hence why I ignored that factor.

Are you alternate day dosing on EI, or dosing both micros and macros every day?

I don’t know if the timing of the micros could be the cause, particularly if you have hard water and are using a EDTA chelate, as the higher pH when the lights are off could be causing the iron to precipitate out of solution. Then when you add your micros it could be taking a couple of hours for the plant to uptake the newly available source.

I’ve no idea if it can happen all that quickly though - you probably need @dw1305 to wade in on this.
 
Low nitrate is possible with hard water - my tap water is hard but nitrates are around 5ppm, but I figured you were on EI, hence why I ignored that factor.

Are you alternate day dosing on EI, or dosing both micros and macros every day?

I don’t know if the timing of the micros could be the cause, particularly if you have hard water and are using a EDTA chelate, as the higher pH when the lights are off could be causing the iron to precipitate out of solution. Then when you add your micros it could be taking a couple of hours for the plant to uptake the newly available source.

I’ve no idea if it can happen all that quickly though - you probably need @dw1305 to wade in on this.
Sorry i should be more clear:

I daily dose both macro and micro, macros 3 hours apart from from micros.

My total weekly dose is:
20ppm NO3
6ppm PO4
30ppm K
13ppm MG

0.6ppm fe as a proxy for APF traces. (EDTA doesn't work as my PH doesnt drop below 7)
0.3ppm fe DTPA
0.3ppm fe EDDHA

Lighting is twinstar 900S 10cm above the water line, 7 hour photoperiod total. (No natural light)
 
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Not that I can recall. As far as I know it's a permanent thing. Not something that can occur as a diurnal consequence of the photoperiod. But hey the universe is a strange and wonderful place, so who am I...
 
Not that I can recall. As far as I know it's a permanent thing. Not something that can occur as a diurnal consequence of the photoperiod. But hey the universe is a strange and wonderful place, so who am I...
It's very strage and has stumped me. My photos from my previous posts about pale rotala must have been taken at the beginning of the photoperiod.
 
Ever heard of/experienced this? What are your theories?

My wife goes a little red after a day in the sun, not sure if its related to the rotala going red towards end of photo period :rolleyes:
 
Daily increase in amount of Phosphates within top areas of the plant exposed to strong light (P is highly mobile within plant tissue) and producing carotenoids (or anything similar like anthocyanins which are water soluble so potentially can increase/decrease during the day) to protect and compensate low amounts of chlorophyll we can see in the first image? If the 2nd image is accurate, they are not more green, they rather look like more green with yellow or orange hue added.

Or @Zeus. wife case which in the end works in the same way ;)
 
are the lights at exactly the same output in both images, a reference card would be hand in the image, but it does look like a fair old change between the two images
Yes both at 100%.

Daily increase in amount of Phosphates within top areas of the plant exposed to strong light (P is highly mobile within plant tissue) and producing carotenoids (or anything similar like anthocyanins which are water soluble so potentially can increase/decrease during the day) to protect and compensate low amounts of chlorophyll we can see in the first image? If the 2nd image is accurate, they are not more green, they rather look like more green with yellow or orange hue added.

Or @Zeus. wife case which in the end works in the same way ;)
Yes the photos are accurate just taken 5hours apart. The room lighting is the same too, as you can see the h.pinnatifida is pretty much exactly the same in each photo while the rotala takes on the change. I will try get some more shots tomorrow from above and the same angle for more accuracy. But the change is definitely quite dramatic as you can see.
 
The first photo is 1.5 hours into photo-period, all the tips look really pale and white. The second photo taken the same day at 6 hours into photo-period and as you can see they have coloured up so you can see more vibrant greeen and orange.

I've seen this in my own plants - thought I just stared at them too much. Misery loves company.

Totally a guess: It may be new tissue that grew overnight and the plant hasn't decided how much chlorophyll to put into it yet? It may "know" how close it is to the top and is just scared to waste resources?

Another thought: Maybe nitrogen rich conditions ... when nitrate limited, it has no choice but to be red --- when nitrogen is plentiful, it can adapt in real time? I am looking to lean my dosing soon and also reduce my minerals, so I will see if that removes this observation.


Josh
 
Hi all,
.........you probably need @dw1305 to wade in on this.
I'm not a lot of help I'm afraid. My guess is that it relates to changes in the chlorophyll / anthocyanin ratio. We have a good <"anthocyanin thread">.

I'm pretty sure the plants are iron (Fe) deficient (partially because they are <"Rotala in hard water">), but the plant can't move any iron to the leaf tissue, iron isn't mobile within the plant, so the colour change during the photoperiod isn't directly iron related.
Maybe nitrogen rich conditions ... when nitrate limited, it has no choice but to be red --- when nitrogen is plentiful, it can adapt in real time?
Anthocyanins are held inside the cell in the vacuole, which means they are underneath the cell layer that contains <"the chlorophyll">. Assuming the plants are greener at the end of the photoperiod, they have more chlorophyll. You certainly get a very rapid greening when you add nitrogen (when it is deficient), presumably because the plant can rapidly produce more chlorophyll.

The problem is that there has to be available iron to <"synthesise more chlorophyll">.
The photosynthetic ability of higher plants has long been known to be adversely affected by iron deficiency. The primary response associated with the unavailability of iron is the loss of chlorophyll. This paper focuses on the role played by iron in the biosynthesis of chlorophyll and its precursors. Special emphasis is placed on the involvement of iron in the formation of δ‐aminolevulinic acid (ALA), the initial committed step in chlorophyll formation........

cheers Darrel
 
Hi all,

I'm not a lot of help I'm afraid. My guess is that it relates to changes in the chlorophyll / anthocyanin ratio. We have a good <"anthocyanin thread">.

I'm pretty sure the plants are iron (Fe) deficient (partially because they are <"Rotala in hard water">), but the plant can't move any iron to the leaf tissue, iron isn't mobile within the plant, so the colour change during the photoperiod isn't directly iron related.

Anthocyanins are held inside the cell in the vacuole, which means they are underneath the cell layer that contains <"the chlorophyll">. Assuming the plants are greener at the end of the photoperiod, they have more chlorophyll. You certainly get a very rapid greening when you add nitrogen (when it is deficient), presumably because the plant can rapidly produce more chlorophyll.

The problem is that there has to be available iron to <"synthesise more chlorophyll">.


cheers Darrel
Do you think it's even possible for me to be no3 dificiant? Even when dosing 20ppm and my water containing 30ppm (80% water changes)

I am about to make a new batch of ferts, so i'll bump up the DTPA a bit and see what happens over the next month. My other plants don't have an iron deficiancy, so what you said about rotala growing in hard water probably is one of the main causes.
 
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It would be interesting, as an experiment, to dose your micros an hour or two earlier to see if the rotala greens up earlier? It may also help Fe availability as DTPA chelate is broken down more rapidly by exposure to light I believe.
 
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