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Stunted rotala green, CO2 already seems excessive - any ideas?

xZaiox

Member
Joined
31 Mar 2022
Messages
344
Location
Maidstone, UK
Hi guys,

My rotala green has stunted growth, and from my understanding the most likely cause will be CO2? The tank is EI dosed with ferts.

Anyway, my pH degassed for 24 hrs is 8.2, and having just measured my tank at the end of the day, the pH appears to be 6.55?? I initially tested with API liquid pH test, but that number seemed like a crazy high swing to me, so I then calibrated my pH pen with fresh buffer powder and sure enough... yup, 6.55. My drop checker in the tank appears lime-green, but if the drop checker is taken out of the water then it looks strongly yellow. My fish breathe faster but don't gasp at the surface, although my shrimp aren't very active while the CO2 is on. I've been just slowly raising the CO2 until I believe the fish show distress, but surely a 1.7 pH drop isn't safe already? I feel apprehensive to push it further, but I also want this stunted rotala growth to improve.

My dKH is about 10, and dGH about 20. Light is a twinstar 900s currently dimmed to 40% with a 6 hour photoperiod, CO2 comes on 4 hours before lights and is stable within 0.1 pH. I'm currently dosing full EI with extra FeDTPA and FeEDDHA due to the hardness of the water. The flow could probably be improved in parts of the tank, but this patch of rotala in the pictures is in the path of a strong flow, all leaves sway in the current.

Any ideas? I'm wanting to know whether this CO2 is already too much or should be pushed further, as well as what typically causes stunting in this plant.
 

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Hi
I would reduce the Co2 dosing till you have a green drop checker, you are very close to gassing your inhabitants!
There are various threads on Rotala issues!
Here is one below.

Rotala stunting can be a consequence of various issues not enough light....not enough Phosphate, too much Potassium, a interaction of Fe and Phosphate, fertilizer over accumulation etc.
I would stop dosing any ferts for a few weeks trim off the stunted Rotala growth and monitor the growth.

More information would be helpful....with a close up images of also other plants!
hoggie
 
The only suggestion I would add to the points above is to let us know how old the plant are, how they were cultivated prior to planting, and if you have it the name of the plants. From what I remember, there are three species, numerous sub-species and varieties. I would expect dense planting is more of a problem depending upon these factors. I counted around 90 stem apexes, so presumably they need to grow outwards to achieve more light and there is a plan for trimming and replanting if applicable. I have found that dense planting can slow the early stages of growth more in the corners of aquariums.
 
Hi guys,

My rotala green has stunted growth, and from my understanding the most likely cause will be CO2? The tank is EI dosed with ferts.

Anyway, my pH degassed for 24 hrs is 8.2, and having just measured my tank at the end of the day, the pH appears to be 6.55?? I initially tested with API liquid pH test, but that number seemed like a crazy high swing to me, so I then calibrated my pH pen with fresh buffer powder and sure enough... yup, 6.55. My drop checker in the tank appears lime-green, but if the drop checker is taken out of the water then it looks strongly yellow. My fish breathe faster but don't gasp at the surface, although my shrimp aren't very active while the CO2 is on. I've been just slowly raising the CO2 until I believe the fish show distress, but surely a 1.7 pH drop isn't safe already? I feel apprehensive to push it further, but I also want this stunted rotala growth to improve.

My dKH is about 10, and dGH about 20. Light is a twinstar 900s currently dimmed to 40% with a 6 hour photoperiod, CO2 comes on 4 hours before lights and is stable within 0.1 pH. I'm currently dosing full EI with extra FeDTPA and FeEDDHA due to the hardness of the water. The flow could probably be improved in parts of the tank, but this patch of rotala in the pictures is in the path of a strong flow, all leaves sway in the current.

Any ideas? I'm wanting to know whether this CO2 is already too much or should be pushed further, as well as what typically causes stunting in this plant.

1651388357872.png


There is a school of thought that says that plant problems reported in UKAPS are due to 'imperfect' CO2, hence your reaction to continue to increase the CO2 to solve stunting is perfectly understandable. Yet, despite 1.7pH drop and yellow drop checker, your Rotalas are still stunted....

However, there is another school of thought, which I should caveat is hotly disputed by some, that EI + hard water may be contributing to the stunting of the Rotala.
 
Hi
It well could be the case that Rotala sp....maybe sensitive to and having a reaction to an individual Macro/Micro element dosed into the water column!
I would do small water changes over a few weeks to remove most of the fertilizers, refrain from dosing in that time and observe new growth on the Rotala.
 
Hi
I would reduce the Co2 dosing till you have a green drop checker, you are very close to gassing your inhabitants!

Hi Hoggie, thank you for this comment. Honestly, I've been feeling this way myself too, but I've just read so much advice from the likes of Tom Barr / Clive about how critical CO2 is and to keep turning it up, and given the plant growth isn't going as well as I would have hoped, I figured it must be CO2. Today was water change day, and the fish do breathe significantly slower after a water change, so I would definitely prefer to have lower CO2 levels, and I've now lowered the rate accordingly.
Rotala stunting can be a consequence of various issues not enough light....not enough Phosphate, too much Potassium, a interaction of Fe and Phosphate, fertilizer over accumulation etc.
I would stop dosing any ferts for a few weeks trim off the stunted Rotala growth and monitor the growth.

Do you think my twinstar 900s set to 40% is providing enough light? From my understanding this is a high intensity light with high par values, so I would have thought even at 40% the light should be adequate? It's interesting that you advise NOT dosing ferts - have you personally seen improvements from lowered dosing? And would it be more sensible to instead dose like 1/2 or 1/4 of EI? Because the plants still do need nutrients don't they? I'm doing 50% water changes every Sunday.

The only suggestion I would add to the points above is to let us know how old the plant are, how they were cultivated prior to planting, and if you have it the name of the plants. From what I remember, there are three species, numerous sub-species and varieties. I would expect dense planting is more of a problem depending upon these factors. I counted around 90 stem apexes, so presumably they need to grow outwards to achieve more light and there is a plan for trimming and replanting if applicable. I have found that dense planting can slow the early stages of growth more in the corners of aquariums.

Hi Simon, these plants are roughly 2 months old now, and the rotala was lab cultivated (tropica's 1-2 grow), the name is Rotala rotundifolia 'Green', purchased here - Rotala rotundifolia 'Green' Tropica 1-2 Grow!

It's interesting that you mention plant density, these were planted as about 3-4 stems bunched together and then spaced, should the stems have been planted individually?

There is a school of thought that says that plant problems reported in UKAPS are due to 'imperfect' CO2, hence your reaction to continue to increase the CO2 to solve stunting is perfectly understandable. Yet, despite 1.7pH drop and yellow drop checker, your Rotalas are still stunted....

However, there is another school of thought, which I should caveat is hotly disputed by some, that EI + hard water may be contributing to the stunting of the Rotala.

Hi Erwin, thank you for your input, this is an interesting take. You're completely right about the 'imperfect co2' part, that is the exact reason why I have been increasing my CO2 further and further, it's all Tom Barr and Clive seem to say to do. Yet I've tried looking into how extreme a pH drop people are getting, and the highest I found commonly reported was 1.3-1.4, so my 1.7 drop seemed crazy to me too, yet here we are with the stunting...

What is generally advised to counter this? Because the plants obviously still need nutrients, so how much should be dosed in hard water?

More information would be helpful....with a close up images of also other plants!

Certainly! Here you go -

Full tank shot

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Rotala rotundifolia 'Green' - Stunted

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Limnophila hippuridoides - Old growth is shedding, new growth seems better but quite pale/light, unsure if this is normal for the plant?

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Blyxa Japonica - Sorry, not the best shot, the new growth seems a good colour. It gets filamentous diatoms build up in it, but I think this is because the shrimps love it and it likely collects some detritus from them. Easy to vacuum out.

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Micranthemum Monte Carlo - Unsure about this one... some of the growth looks healthy whereas other parts don't. It doesn't grow very fast though.

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Pogostemon helferi - Seems okay? The specs on it are sand... My dwarf rams keep spitting sand on it lol.

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Hottonia palustris - The old emersed growth of this melted quite early on, but the new growth seems quite healthy?

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Murdannia keisak - Unsure about this, the new growth usually seems okay but it tends to get small amounts of algae or diatoms on the older leaves.

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Bucephalandra kedagang - This one is a newer addition, it hasn't been in the tank too long. The old emersed growth appears to have developed some algae, and the new growth it's throwing out seems like an odd colour, unsure if this is normal?

IMG_8131.JPG


Java ferns - There are 3 different species I have in here, Microsorum Pteropus, Microsorum Narrow Leaf, and Microsorum pteropus Trident. These java ferns have all done the same thing - The original emersed growth has slowly been getting covered in algae, but the new growth that they throw out seem really healthy (to me at least?). I was unsure why many of the new leaf tips are translucent, but looking online, this seems to be normal for the species? None of the new growth seems to get algae.

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Hygrophila polysperma 'Rosanervig' - This seemed to grow faster when it was first put in the tank from an emersed from, whereas now it's not growing quite as quickly, but I'm wondering if that might be because it's developed the submersed white appearance? Less chlorophyll? It doesn't seem to have algae at least...

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Hygrophila Compacta - I would say for the longest time that this was the healthiest plant in the tank, however there appears to be some mechanical damage on it show up recently (the holes). Not really sure what's causing that, because I don't have any plecos or rasping fish. I do have amano shrimp though? Perhaps a point to note, this plant is in the path of the strongest flow in the tank, so it likely has access to the highest amounts of nutrients/CO2. All leaves sway in the current.

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Pogostemon erectus - This gets filamentous diatoms build up in it but I'm assuming it's because the shrimp litter it and it's quite bushy. They vacuum out easily. I'm unsure about the growth, the new growth on top seems quite pale to me? Unsure if this is normal for the species, however, the plant grows quite reasonably and is getting to a nice size.

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And lastly, here's a shot of my fish being nosy and following me around the tank while I take pics 😀:lol:

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Don't know if any of that helps? Would love further feedback.
 

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Hi
Sorry I cant help you with the lighting as I never had a Twinstar, 50% would be reasonable I think!
If your doing regular water changes these will have a certain level of nutrients for the time being.
Remember Co2 is actually a fertilizer.... therefore keep a green drop checker and try moving a few Rotala stems to another area of the aquarium.
I have similar water parameters as yours, cutting back or stopping fertilization has helped Rotala recover in my case!
hoggie
 
I've had another look at the Rotala Image....they don't seem to be stunted.
The other plants look healthy.
Try increasing your lighting percentage and duration to 7 hours!
Below is a good example of stunted Rotala.
1651430744059.png

hoggie
 
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It's interesting that you mention plant density, these were planted as about 3-4 stems bunched together and then spaced, should the stems have been planted individually?
Individual planting doesn't matter very much in my experience when there is enough light and they are not too densely planted, and overall I find it longer for in-vitro plants to start growing when compared to cuttings. I wouldn't worry.
 
I've had another look at the Rotala Image....they don't seem to be stunted.
The other plants look healthy.
Try increasing your lighting percentage and duration to 7 hours!
Hoggie, I'm going to follow your advice. My plan of action now is to increase the lighting, both intensity and duration (to 50% for 7 hours), and reduce fertilisation. Hopefully this will help! Thanks for your input :thumbup:
Individual planting doesn't matter very much in my experience when there is enough light and they are not too densely planted, and overall I find it longer for in-vitro plants to start growing when compared to cuttings. I wouldn't worry.
Thanks for the input Simon, hopefully they'll pick up with a bit more light, I'm going to slowly increase the lighting over the next month or so and watch for growth of plants and algae.
 
@xZaiox was this issue ever resolved? Keen to here how this issue was fixed if so, cheers!
 
@xZaiox was this issue ever resolved? Keen to here how this issue was fixed if so, cheers!
Hey @plantnoobdude - Sort of, yes. The filamentous diatoms I was having in my tank are now gone, and for the most part the tank is in good condition. Here's a couple pics of the rotala - I'd say it's doing "okay" now, but the leaf blades aren't quite as long and attractive as I've seen in other pics online. Btw the other stem plants at the back in the pics (limnophila hippuridoides and pogostemon erectus) aren't stunted, I've just cut them back because I made an error in not pruning them as they grew in, so they weren't as bushy as I wanted them to be, they've been growing fine now, just waiting for them to fill in again.

I'm now sure the issue definitely isn't / wasn't CO2, I've actually reduced my CO2 usage now for the benefit of my fish. Before my pH was dropping from 8.2 to 6.55 (as I said in the original post), and now I have it drop to 7.0 instead and have seen no harm come from the reduction. The rotala just gradually started doing better, I think as @Simon Cole said above -
overall I find it longer for in-vitro plants to start growing when compared to cuttings
I personally am now thinking it was due to (1) the rotala taking a while to get used to the tank conditions due to being in-vitro, (2) my tank not being mature, (3) I also think my water being liquid-rock levels of hard may be causing issues with plant growth, but that's purely speculation on my part. I did also increase my lighting percentage after the diatoms went away, it's currently at 80% (up from 40% in the original post).

The rotala (and others) started doing better shortly after I made the original post, so I didn't end up cutting my EI dosing - I'm still dosing full EI. Overall, I'm happy with how my tank is doing now, I have a few kinks to iron out, but I truly do now understand why everyone says that this hobby is all about patience - things apparently take time :lol:
 

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Simon Cole said:
overall I find it longer for in-vitro plants to start growing when compared to cuttings
(1) the rotala taking a while to get used to the tank conditions due to being in-vitro

This matches my experience as well, across 5+ different varieties of Rotala rotundifolia.
The invitro plants are just so small, their capacity for growth seems to be limited for a while, but then once they finally reach full size they grow much faster.
I see it like an old fashioned locomotive train. When the train first starts moving its going at a slooow crawl, but once it has built up enough speed it will go quite fast despite the massive size.
Ive found plant growth relative to plant mass to be much the same
 
Here's a couple pics of the rotala - I'd say it's doing "okay" now, but the leaf blades aren't quite as long and
Yes, they do not look optimal. Definitely see some improvement though.
Any close ups?

As for the establishing part, that could be true. While it may take a tc bunch of plants 6 weeks to reach the top of the tank, once the stems establish they may need to be trimmed every two weeks! Though I am not sure I ever observed any stunting in establishing plants.
 
The invitro plants are just so small, their capacity for growth seems to be limited for a while, but then once they finally reach full size they grow much faster.
Yeah this has been my experience too, it grows quite fast now, but took a very long time at the start.
Yes, they do not look optimal. Definitely see some improvement though.
Any close ups?
Sure, I've attached a few here - they definitely aren't optimal, the rest of the plants in the tank are mostly fine though, so I'm kind of hoping this might improve with time. On reflection, I do also think I probably planted too many as bunches, I wouldn't be surprised if they're fighting for nutrients 😬

Also sorry for the quality of the photos... I'm now thinking it may be time to upgrade my iphone lol.
 

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they definitely aren't optimal
1fdhggfg.png

Old growth appears to have somewhat better color than the newest shoots, do you know what you dose of Iron and which chelate?

On reflection, I do also think I probably planted too many as bunches
1gdssdgsd.png

Your picture may be misleading but is this all bare stems under there?
Rotala species are pretty tolerant of being cut back without replanting, but eventually you have to take the tops, throw away the bottoms and replant/restart the bush.
 
Yeah this has been my experience too, it grows quite fast now, but took a very long time at the start.

Sure, I've attached a few here - they definitely aren't optimal, the rest of the plants in the tank are mostly fine though, so I'm kind of hoping this might improve with time. On reflection, I do also think I probably planted too many as bunches, I wouldn't be surprised if they're fighting for nutrients 😬

Also sorry for the quality of the photos... I'm now thinking it may be time to upgrade my iphone lol.
I hope you don’t mind me pointing out some issues I’m noticing,
1. Chlorosis, many new leaves look pale.
2. Necrosis old leaves and stems turn black, healthy plants will not do this,
3. Stunting, the leaves seem to be changing size, some very small and and appear to have some crinkling.
I strongly doubt this is a nutrient deficiency… since you’re dosing ei,
 
I guess its possible for Iron in some circumstances?
But I think this Rotala will be much happier if it gets replanted and receives more flow/CO2, just some renewal too, seems to be a big part of it
I think it could be due to Mn, or Mg.
Op is already dosing huge amounts of iron above Ei.

A while back i kept piling on micros, to help with pale plants. (Specifically tonina) I was using Apfuk micro mix to 1 ppm FE. Weekly!
After this I finally made my own micro mix to 0.1 Fe dtpa and 0.067Mn, the issue resolved shortly.
I would also make sure you have plenty of magnesium.

Iron, manganese and magnesium are all related to chlorophyll production, I also strongly believe ratios could be playing a roll, specifically Fe:Mn. I suggest a 2:1 ratio.

Might I suggest adding additional manganese, and magnesium? In addition to proper plant husbandry techniques that hufsa outlined.
 
Old growth appears to have somewhat better color than the newest shoots, do you know what you dose of Iron and which chelate?
Yeah, so multiple of plants seem to have discoloured new leaves that eventually colour up normally, I had assumed it was iron as well (I've made a post on ukaps about it), and added additional iron chelates to my dosing regime, but as you can see, the rotala still shows the discoloured growth - I was kind of assuming this is just how the new leaves form, but I'm now guessing that's wrong? Also note that they are in a flourite substrate, which from my understanding should contain iron?

I'm currently dosing 1/16 teaspoon of CSM+B, 1/32 teaspoon DTPA chelated Iron, and 1/16 teaspoon EDDHA chelated Iron, all 3x a week.
View attachment 192355
Your picture may be misleading but is this all bare stems under there?
Rotala species are pretty tolerant of being cut back without replanting, but eventually you have to take the tops, throw away the bottoms and replant/restart the bush.
Nah, my light fixture is placed in the middle of the tank, and this is the rotala reaching forward towards the light. I didn't do any pruning at first until the plants reached the top, which I now understand is a mistake because they haven't grown in a tidy fashion. I also didn't realise you had to occasionally fully replant them 😬 how often do you do this? What happens if you just trim them?
 
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