# Dark spots (holes) on Rotala rotundifolia... ?



## maboleth (17 Apr 2019)

Some leaves on my Rotalas feature holes/dark spots. Usually on older leaves, but newish growth have them as well, after some time. The issue isn't big, plants appear healthy overall, but still it's the only plant showing any kind of weakness.

Water parameters:

N: 10-15
P: 1.5
K: 15
Traces/Iron: Profito adding weekly.
CO2: 25mg
Light: 3x T5 39w on 250l tank.

Any ideas? Thanks.


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## ian_m (17 Apr 2019)

Looks like BBA.

Possible causes are:
- Too much light for your CO2 levels.
- Poor levels or poor distribution of CO2.

What is your CO2 and light timing ?
How are you determining your CO2 levels ?


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## maboleth (17 Apr 2019)

Thanks but it's not bba. It's not algae at all. These are tiny holes. 

I determine CO2 on ph/kh ratio and drop checker colour made with 4dh water. Light time is 7,5h.


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## Matt @ ScapeEasy (20 Apr 2019)

Holes in leaves can be due to a lack of potassium... do you think this could be a contributing factor?


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## maboleth (20 Apr 2019)

I could always add more. I guess there's no strict threshold for kalium, meaning there's no side effects of too much.


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## lazybones51 (3 May 2019)

@maboleth Did you make any progress with this issue, as i'm suffering with the same problem with Rotala Rotundifolia in a high tech tank.


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## Konsa (3 May 2019)

Hi all.
I will second @ian_m
Chech your flow CO2 distribution .I had it with Rotala green in my last high tech.Classic CO2 issues for Rotalas.
Was growing fine one day as the plants grew in(high plant mass inhibits flow too) the lower 2/3 of the plant developed same black spots and tyni holes while the top third grew well and was pearling a lot. Trim and clean of filter pipework sorted it.
Regards Konsa


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## maboleth (4 May 2019)

lazybones51 said:


> @maboleth Did you make any progress with this issue, as i'm suffering with the same problem with Rotala Rotundifolia in a high tech tank.



@lazybones51 Actually yes. I did nothing in particular, but the plants changed the environment several weeks before those issues started to appear. So I guess the leaves with holes were those that grew in time of adaptation and stress. Sorry that I cannot help more, but check what Konsa said.

As for my tank, CO2 distribution is unlikely. I measure CO2 in the furthest part of the tank (furthest from the CO2 supply that is), very close to Rotalas. And it's bright green.


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