Rotala changes colour daily.....

[Sammy I]

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.

Interesting, i could dose micro an hour before lights, my ph should be low enough to keep the DTPA stable. Resting ph is 7.9, with co2 ph7.1, very lime green drop checker at lights on, essentially yellow.

 

[dw1305]

Hi all,

possible for me to be no3 deficient?

No, I'm pretty sure it isn't a nitrogen deficiency. It is back to the <"assembly line aspect"> of <"Liebig's law of the minimum">, adding more of a non-limiting nutrient doesn't give you any more growth.

New leaves that pale definitely suggest a shortage of chlorophyll, and chlorosis in new leaves is very likely to be iron (Fe) related.

Have a look at @Konrad Michalski 's <"Rotala rotundifolia - Growth Issues">.

cheers Darrel

 

[Sammy I]

Hi all,

No, I'm pretty sure it isn't a nitrogen deficiency. It is back to the <"assembly line aspect"> of <"Liebig's law of the minimum">, adding more of a non-limiting nutrient doesn't give you any more growth.

New leaves that pale definitely suggest a shortage of chlorophyll, and chlorosis in new leaves is very likely to be iron (Fe) related.


Have a look at @Konrad Michalski 's <"Rotala rotundifolia - Growth Issues">.

cheers Darrel

Thanks, I've read that a few times, i shall revisit it. That's when i started to add EDDHA, i guess i'll increase FE in DTPA form for next months batch of ferts that I'm about to mix.

 

[dw1305]

Hi all,

That's when i started to add EDDHA,

Not sure now, that should supply some iron (Fe). Does your water have a pink tinge?

cheers Darrel

 

[Sammy I]

Hi all,

Not sure now, that should supply some iron (Fe). Does your water have a pink tinge?

cheers Darrel

Yeah by the end of the week the water is slightly coloured, probaby noticeable from thursday onwards. i spread it over 7days now, it was more noticeable when dosing EI alternate days (3x a week). I dose both DTPA and EDDHA in my mix

 

[Sammy I]

Here are some more photos i took today.

4.30pm


9pm

 

[X3NiTH]

My Stab in the dark is that this effect is an NO3 efflux>=influx Diurnal Effect.

Firstly I’d be swapping around dosing with Micro 3 hours before lights on and Macro at lights on because NO3 isn’t uptaken in the dark, it requires photosynthesis to be active for the plant to uptake it, also most Iron chelates don’t like light so dosing away from the photoperiod increases its maximum availability for longer. The plant will still efflux NO3 in the dark as part of the Nutrient transport mechanism and this efflux is increased in the root zone by the stress of a more Acid medium (co2 will do that, doesn’t have to be below neutral pH), so it’s another good excuse to degass co2 quickly for the dark period to reduce the possibility for this effect. I would also increase your lighting period a little so the plant has longer time to influx lots more Nitrate so that there hopefully isn’t a shortfall anymore where efflux>=influx with the visual appearance of pale leaves in the morning and vibrancy by the end of the photoperiod.

🙂

 

[Sammy I]

My Stab in the dark is that this effect is an NO3 efflux>=influx Diurnal Effect.

Firstly I’d be swapping around dosing with Micro 3 hours before lights on and Macro at lights on because NO3 isn’t uptaken in the dark, it requires photosynthesis to be active for the plant to uptake it, also most Iron chelates don’t like light so dosing away from the photoperiod increases its maximum availability for longer. The plant will still efflux NO3 in the dark as part of the Nutrient transport mechanism and this efflux is increased in the root zone by the stress of a more Acid medium (co2 will do that, doesn’t have to be below neutral pH), so it’s another good excuse to degass co2 quickly for the dark period to reduce the possibility for this effect. I would also increase your lighting period a little so the plant has longer time to influx lots more Nitrate so that there hopefully isn’t a shortfall anymore where efflux>=influx with the visual appearance of pale leaves in the morning and vibrancy by the end of the photoperiod.

🙂

Wow thanks, very interesting. I'll give it a go, i've wanted to increase photoperiod for ages but just put it off as things are going well.

If i was to dose micros first, i would need to wait until the co2 drops my ph below 7.5 for the DTPA to be stable and most effective?

 

[alto]

Do you have iron supplements in the substrate?

Have you considered decreasing GH (mixing tap and RO) while keeping all else consistent?
(ie, buying RO if there’s a convenient affordable local source)

 

[Sammy I]

Do you have iron supplements in the substrate?

Have you considered decreasing GH (mixing tap and RO) while keeping all else consistent?
(ie, buying RO if there’s a convenient affordable local source)

Yeah i put in root tabs every now and again, i have loaded up twice since the 5month mark.

RO is afforable and easy to get from lfs but i really dont fancy having to get water all the time considering things are doing well in general and i don't love my tank that much to go to the extra effort 😛 The last time i checked i think i had:
GH 22/23
KH 12/13

 

[Sammy I]

Bump post

Still have this weird problem and i would like some more thoughts. Since starting the thread i have tried a few things but nothing has fixed it.

I'm not sure if it is a deficiency, but realistically It's definitely not a NO3 deficiency. It's not a trace element deficiency i have dosed more etc.

I don't think its FE either as my usable FE comes from DTPA and EDDHA and my other plants look decent enough and the colour change happens over the same photoperiod.

I think it may have something to do with PO4, maybe a defiency as my PH doesn't dip below PH7. It could be what was mentioned earlier in the thread about PO4.

I have noticed that when my lights turn on and ramp up the rotala don't look pale, it's when the lights are at 100% it takes the rotala a couple hours to "catch up" and colour up.

 

[Guest]

You sure it's not to do with light intensity?
Is it programmed to change throughout the day?

 

[Sammy I]

You sure it's not to do with light intensity?
Is it programmed to change throughout the day?

Stable lighting during photoperiod, twinstar 900SA 13-14cm above the waterline.
Controller thingy settings:
2.30pm 0%
3.15pm 100%
9.45pm 100%
10.30pm 0%

 

[Guest]

Could be a perception issue unique to your eyesight, personally I can't really see a marked difference between the before and after images...

 

[Sammy I]

Could be a perception issue unique to your eyesight, personally I can't really see a marked difference between the before and after images...

First half of the photoperiod the tips are pretty much white or very pale, and second half they colour up more (maybe not fully?) and the whiteness it gone leaving more orange, green and pinky colours.

Probably more evident side by side rather than how i posted before. If you click the photo and go into "light box mode" you can flick between the photos quickly for even more impact 🤣

 

[Mortis]

In order to add to the confusion, Im seeing the same thing with my UG since the last few months. Its pale in the morning, before and after the lights just come on and gets back to its normal healthy bright green by the end of the day. Since its purely a green plant I think we can rule out the concentration of red pigments as with rotala sp.
Ive tried various things over the last few months, giving enough time in between for the plants to adapt to the changes but no luck.

1] Increased Nitrates by 25% + adding an extra spoonful once a week - no change even though Im dosing full EI for my tank and its currently sparsely planted
2] Increased Iron, both EDTA & DTPA, I usually add 25% by volume more DTPA FE to my CSMB solution so I have a mix of chelated iron. Increased both and no change.
3] Increased CO2 - no change
4] Stopped dosing Excel in case the UG had suddenly become sensitive to it - no change
5] Decreased and increased light alternatively - no change
6] Thorough gravel vac and filter clean in case it was due to excess organics - no change
7] Shifted it from the foreground only to a patch running front to back on sloped substrate to see if proximity to the light had any effect - no change

Honestly Im stumped. Its a very sensitive plant as we all know and Ive had good success with it for the last few years. Although its pale, the leaves are heathy in terms of strength and it takes off easily enough after replanting.

Any suggestions ?

 

[Sammy I]

I had an idea last night after a message from @alto. I realised that my tank gets no sunlight at all, i don't open my blinds so the room is fairly dark until the photoperiod. So the only light my tank gets is literally from the twinstar light.

My next experiment will be to open my blinds slightly a couple of hours before the photoperiod start and allow daylight into the room with no direct light hitting the tank. My CO2 will be already on at that time and i will have more than enough ferts already in the water column especially FE. Will report back in a couple of weeks to see if it makes a difference.

 

[Sammy I]

Don't think letting in some daylight has made any difference so i'm pretty stumped.

Maybe they are running out or can't move a mobile macro nutrient during the first half of the photoperiod and then moving it up the plant later on from the soil? PO4 availability in PH above 7?

I've increased my CO2 a tiny bit more so will continue to observe. @ceg4048 and @Christel could you please possibly shed some light on what could be going on here please? 😀

 

[Christel]

An answer is not easy and of course I could be wrong. I have not observed this daily color change in Rotala rotundifolia in my aquariums so far. That is very interesting. It is difficult to make a remote diagnosis, but perhaps there could be the following explanation:

When the light comes on (12 hours total would be ideal), the plants begin to assimilate. When a plant reaches the highest assimilation rate (rapid growth) during the day varies from species to species. So when the light comes on, Rotala will not have an assimilation rate of 100 % right away, but will reach the peak of assimilation only after some time (one or two hours?). The assimilation of this species does not necessarily have to remain constant the day over, but if the light is too intense, the assimilation rate can also decrease again (e.g. in shade plants) – then the plants grow slower! The reddish colouring (what we like) is to be seen as a common reaction (protection) against too intense light. The reddish colouring does not mean that the plants grow faster. I think that the colouration of your plants, Sammy, depends on both the speed of growth (assimilation) and the light intensity. I think it has nothing to do with nutrients.🙂

 

[Sammy I]

An answer is not easy and of course I could be wrong. I have not observed this daily color change in Rotala rotundifolia in my aquariums so far. That is very interesting. It is difficult to make a remote diagnosis, but perhaps there could be the following explanation:

When the light comes on (12 hours total would be ideal), the plants begin to assimilate. When a plant reaches the highest assimilation rate (rapid growth) during the day varies from species to species. So when the light comes on, Rotala will not have an assimilation rate of 100 % right away, but will reach the peak of assimilation only after some time (one or two hours?). The assimilation of this species does not necessarily have to remain constant the day over, but if the light is too intense, the assimilation rate can also decrease again (e.g. in shade plants) – then the plants grow slower! The reddish colouring (what we like) is to be seen as a common reaction (protection) against too intense light. The reddish colouring does not mean that the plants grow faster. I think that the colouration of your plants, Sammy, depends on both the speed of growth (assimilation) and the light intensity. I think it has nothing to do with nutrients.🙂

Thank you for the input, i did think it was something to do with lighting, that's why i have been opening my blinds to give the tank some natural (non direct) light.

I have also observed that when the lighting turns on and ramps up over 45min, the plants do not look pale. It is only when the lights are at 100% they become/look pale and then slowly regain their colouration after a couple of hours.

I think i will carry on with more natural light before my photoperiod, especially as the days are beginning to look less gloomy. I will report back soon.