Lowtech tank unknown issue with easy plant

[Heelllooo]

Hello all

Following the advice of a fellow forumer, I seek advice over some issue I have with certain sp. in my first tank 60L Lowtech.

3 " easy " species and an unidentified specimen are having issues in my tank. Which is weird since some plant categorize as "moderate" or even "hard" do really well like Pogostemon helferi and Rotala walichii which are growing like crazy.

Hardware
26 Watt cheap Led Light from Amazon ( not RGB )
400L/h internal filter directed a little bit against the backwall to reduce the flow in the tank
A 100W heater set to 25°C

Stocking
a female Betta
6 Amano shrimp
3 Nerite snails
2 Neocarina shrimp

Water parameter
1/5 really hard tap water with 4/5 DI water from the supermarket to which I had 2ppm of Magnesium.
It gets me to around 25ppm CA / 5ppm Mg / kH=3
I dose macro and micro on alternate day for a total a week of :
17ppm NO3
1,7ppm PO4
24ppm K
Easy life Profito equivalent to 0,16ppm Fe
+ I add 1ppm of Mg mid-week

Now the issue :

Hygrophila coymbosa, Althernanthera lilacina and the unidentified plant are getting pinholes on the older leaf which are then shredded even more by the Amano and they melt at the base of the stem. And they are getting green dust algae on the older leaf too.

Eleocharis parvula, planted a little more than a month ago, as stopped melting but doesn't grow at all.

And the unknown species that you could maybe help me identify.

For those using the Duckweed Index, I want to had that i have a lot of emersed and floating plant growing which show no sign of deficiency.

I know pinhole sometimes mean K deficiency but since I'm dosing near EI level and my floating plant don't show anything i don't think it's the case.

I'm maybe gonna add a little bit more PO4 and micro in the future since they are on the low side compare to the other nutrient.

But I would lean more toward a CO2 deficiency issue but those plants are suppose to do well without CO2 and they are not the most ill-placed in term of flow.

I can't augment the flow due to my betta really not liking it. So I've let the floating plant cover all the surface over those plant to reduce the CO2 demand but it did not have much positive result . They now die faster than they grow but the algae has receded a little.

I'm really perplexed like i'm blasting the full light over the Rotala Wallichii which is supposed to need CO2 without any problem (except a bit of hair algae ) but the Hygrophila, which is supposed to be one of the easiest genus in the hobby is dying.

Thanks in advance for the response.

 

[Heelllooo]

I forgot to say that i change 25L of water per week.

 

[Hufsa]

Amano shrimp damage for sure 😊

 

[Andy Pierce]

'Unknown species' to me looks like Lysimachia nummularia 'Aurea' (Golden Creeping Jenny).

 

[Witcher]

@Heelllooo

I think the main problem here is really low light vs completely unnecessary high amount of ferts vs lack of added CO2 - it doesn't means you need to add CO2 at all but some things could be straightened up. Vast majority of your plants need much stronger light but they don't care about CO2 too much, lower CO2 levels coming from usual equilibrium means only that the plants will grow slower, that's it. But it's a weak light which makes those plants tissue weaker, allowing Amanos and other folks to gnaw on their surface.

if it was my tank I'll:

slowly increase light over few weeks to approx 0.7 - 1W per liter
remove most of the floating plants to not overhadow the ones underneath
decrease overall amounts of macro to approx 30%
keep profito and Mg as it is
remove all dying leaves as they will be a source of future problems - floating organic matter leading to potential algae outbursts
wait 2-3 months for the results

and if that plant in RH bottom side is an Anubias (but maybe I'm wrong, img is a bit unclear), it needs to be exposed to water column completely, so no roots digged in the substrate.

 

[Heelllooo]

Amano shrimp damage for sure 😊

Yes I am guilty of not feeding them a lot since they seems healthy like that ( constantly breeding ) and I have problems with my Betta eating anything that enters the tank to the point of bloating ( even cucumber ahah ).
But there is an underlying issue, as you can see in the first picture the new healthy leaf of the althernanthera is totally untouched.

'Unknown species' to me looks like Lysimachia nummularia 'Aurea' (Golden Creeping Jenny).

Thanks ! It definitely looks like it ! The photo of the emersed form are what I brought.

I think the main problem here is really low light vs completely unnecessary high amount of ferts vs lack of added CO2

I would say that yes the overall health of those plant were better when they received more light but concerning fert I'm pretty happy of the result I had with high fert ! I've double the dose of fert about 2 month ago and it had a positive impact on the plants particularly the emersed and floating plants.

I'm afraid that more light will exacerbate the small algae issue I have. I was under the impression that 0,4W/L was a lot for a low tech.

So I will firstly remove most of the floating plant and do a big trim + cleaning of the tank and see what happens.

And I will try to find a solution to feed the Amanos more often without killing my Betta. If anybody know a solution ?
Right now I'm breaking the algae wafers in small piece and feeding at night when all light are out to limit her ability to find the food with very little success.

and if that plant in RH bottom side is an Anubias (but maybe I'm wrong, img is a bit unclear), it needs to be exposed to water column completely, so no roots digged in the substrate.

Yes it's an Anubia. Only the root are planted, the rhizome is over the substrate and it's doing really well right now. It was having to much light when there was less floating plant though.
It will move in another setup glued on wood in about a month.

 

[Tim Harrison]

For what it’s worth, I think you have too many floaters and not enough light hitting the plants below. It may actually be the cause of the algae problem.

Plants have what is known as light compensation point. Below this they can’t photosynthesise properly and start to die and decay and release organics which will feed algae.

Another knock on effect could be that your floaters are taking all the nutrients since the plants below aren’t able to acquire them due to lack of photosynthesis.

Accordingly your floaters will have a massive competitive advantage with access to full light and atmospheric CO2 so won’t necessarily show any signs of deficiency. It’s a vicious circle.

I know Darrel @dw1305 has good coverage of floaters but I think he also has strong lighting and a 12 hr photoperiod, and uses lean dosing. So his floaters will be a good indicator of overall nutrient status. It’s about balance.

 

[dw1305]

Hi all,

I know Darrel @dw1305 has good coverage of floaters but I think he also has strong lighting and a 12 hr photoperiod, and uses lean dosing. So his floaters will be a good indicator of overall nutrient status. It’s about balance.

I do, but I have ~2/3 coverage in the summer, but in the winter (when there is <"less ambient light">) I thin them down to 1/2 to a 1/3. The <"bottoms of all my tanks"> are dark and gloomy places, summer or winter. I just let the plant mass grow until it has attenuated <"all the available PAR">. Because <"Bolbitis heudelotii"> (and <"some mosses">) have <"very low LCPs"> they are the plants near the bottoms of my tanks.

For those using the Duckweed Index, I want to had that i have a lot of emersed and floating plant growing which show no sign of deficiency.

They look very healthy.

Amano shrimp damage for sure

It is, possibly because the plant is already struggling through lack of light.

slowly increase light over few weeks to approx 0.7 - 1W per liter
remove most of the floating plants to not overhadow the ones underneath
decrease overall amounts of macro to approx 30%
keep profito and Mg as it is
remove all dying leaves as they will be a source of future problems - floating organic matter leading to potential algae outbursts
wait 2-3 months for the results

Sounds pretty good advice.

but concerning fert I'm pretty happy of the result I had with high fert ! I've double the dose of fert about 2 month ago and it had a positive impact on the plants particularly the emersed and floating plants.

Because the emersed and floating plants <"have access to atmospheric CO2"> they aren't carbon limited and can make use of the available nutrients, At the moment they are <"very efficiently"> converting the "excess" nutrients you add into plant material.

cheers Darrel

 

[_Maq_]

I know pinhole sometimes mean K deficiency

It's an often repeated wisdom and I doubt it very much.

I think the unknown plant is some Ludwigia. See Lysimachia here: Maq's low-tech troubles .

 

[Heelllooo]

@_Maq_ , @dw1305, @Tim Harrison, @Witcher,

First of, thanks for the help.

So I have remove maybe half of the floating plant now and I did cut all the affected leaves ( which i do regularly anyway).

But I'm sorry to say that I'm seriously skeptical that it's gonna stop the problem. It's gonna help my plant grow better surely but like I said in my first post I did let the floating plant go wild as an attempt to stop the pinhole/melting/dust algae issue. So the problem was existing before, when those plants were getting a lot more light.
Maybe I'm totally wrong but like I said I did understand by reading other thread on this forum that 0,4W/L Led ( more than 30 lumen/L ) is a lot for a Lowtech.
Note that I'm running the light at 100%.
The Tropica website put it in the medium light range and it should be more than enough to grow Hygrophila corymbosa.

For example :

I can't comment on the saturation point but can say that light compensation point of some Hygrophila sp is fairly low. Here we have Corymbosa "siamensis" with about 18 ~ 20 par at substrate, or in layman's terms 1 14.5w led in a 1200mm tank .
View attachment 208070

And maybe I'm gonna try reducing the nutrient level slowly until I see deficiency in the floating plant too.
But I'm skeptical too that it will help alleviate the issue, aren't excess nutrient supposed not to be a problem ? EI dosing work because of that, no ?

Sorry if I sound a bit ungrateful, i'm not. I'm really thankful for the time you took to respond and help me.
And maybe i did misunderstood everything, in which case i would like to be corrected and educate.

Thanks in advance for your response.

 

[MichaelJ]

Water parameter
1/5 really hard tap water with 4/5 DI water from the supermarket to which I had 2ppm of Magnesium.
It gets me to around 25ppm CA / 5ppm Mg / kH=3
I dose macro and micro on alternate day for a total a week of :
17ppm NO3
1,7ppm PO4
24ppm K
Easy life Profito equivalent to 0,16ppm Fe
+ I add 1ppm of Mg mid-week

But I'm skeptical too that it will help alleviate the issue, aren't excess nutrient supposed not to be a problem ? EI dosing work because of that, no ?

Generally, somewhat excess in nutrients is not a problem just unnecessary, but it depends on what is in excess and how they relate and interact with other nutrients.

In your case it's a heck of a lot of fertilizer for a low tech tank considering your relatively moderate plant mass. I have two very similar tanks, very densely planted. In comparison my weekly NO3, PO4, K equivalents in one tank are:

N 0.5 ppm = 2.2 ppm of NO3
P 0.04 ppm = 0.134 ppm PO4
K 0.4 ppm
Fe 0.03 ppm weekly

These numbers are just for illustration, I have to stress emphatically that I am not suggesting this meager level of dosing in your case - for starters, your alkalinity/KH is way too high, and so likely your pH and your temperature is on the high side as well.

As suggested above, your plants are likely not getting enough light due to the extensive coverage from the floating plants, which in addition, limits gas exchange.

Cheers,
Michael

 

[Tim Harrison]

Maybe the light was inadequate before the floaters took over. Not sure if you mentioned it before, how long has the tank been running?

 

[John q]

@Heelllooo 👋

Sometimes we can't see the wood for the trees.
Will post a constructive reply later, but for now the pinholes are "Not" due to lack of potassium. Lack of light "Possibly", but unlikely. Lack of co2 possible and likely.

 

[dw1305]

Hi all,

........ But I'm skeptical too that it will help alleviate the issue, aren't excess nutrient supposed not to be a problem ? EI dosing work because of that, no ?....

I don't know, the floating plants look healthy, so that strongly suggests the problems are either light or CO2 related.

Cheers Darrel

 

[Heelllooo]

Not sure if you mentioned it before, how long has the tank been running?

First in November 2022, but I didn't know anything, so I didn't dose fertilizer nor did water change which resulted in a massive cyano and thread algae outbreak in February of this year.

I totally "rescaped" ( if you can call it a scape ahah ) the tank early April. Throwing some plant washing some other but I have kept the same substrate, filter media and all the equipment.
Since then I have been adding other species of plant when I find one that would suit at my LFS.

The 3 species which are having issue right now have been in the tank since November 2022 and are the only plant still in my tank which I did not buy in tissue culture pot.
They were growing relatively well during the first 2 month before showing some sign of deficiency.

 

[Heelllooo]

Sometimes we can't see the wood for the trees.

It certainly is the case

Will post a constructive reply later, but for now the pinholes are "Not" due to lack of potassium. Lack of light "Possibly", but unlikely. Lack of co2 possible and likely.

From my meager knowledge I think it's CO2 related. It's the only parameter I didn't and can't change in the tank.

 

[MichaelJ]

Lack of light "Possibly", but unlikely.

I am somewhat sympathetic to that position... One of my tanks are sometimes incredibly inundated with frogbit and duckweed... which considerably limits lights for the submerged plants and they are fine, but I rarely have that condition for more than a couple of weeks at a time. I don't think it would be sustainable though.

Lack of co2 possible and likely.

more generally lack of gas exchange, more likely yes due to the lack of surface movement and open waters essentially, again I have that conditions once in a while, but rarely for long. For an extended period of time, I would think it would be detrimental to my plants way more so than lack of light.

Being a low tech tank, lowering the temperature and increasing surface agitation are the only remedies I can think of.


Cheers,
Michael

 

[John q]

@MichaelJ I agree with you 💯

@Heelllooo its a simple equation. Aquatic Plants need nutrients in this order: ish.

Liebig's Law is the fundamental building block of life. If you can't supply A, then reduce B.
Us old folks would call it finding the ballance, 😆

 

[MichaelJ]

@MichaelJ I agree with you 💯

@Heelllooo its a simple equation. Aquatic Plants need nutrients in this order: ish.
View attachment 208520

Liebig's Law is the fundamental building block of life. If you can't supply A, then reduce B.
Us old folks would call it finding the ballance, 😆

Render me childish, but I always thought it was hilarious that this scientist name was lie big… and that he has a a law named after him… anyway enough about silly me. Seriously, 96% of plants dry mass made from matter completely unrelated to stuff we actually dose as fertilizer - and 99% if you add N, K and Ca… should give everyone pause. Yes I’m oversimplifying… and I’m old, btw John stop calling me old folks

Cheers,
Michael

 

[Witcher]

Lack of co2 possible and likely.

hmmm... I'm really curious of your findings, personally I think there is absolutely no need to add any additional carbon in any form, at such low levels of light plants won't be even able to build their bodies out of it at acceptable rate, not enough energy coming from the "sun" at all. What I mean is that in the nature plants exposed to even extreme levels of light (equator area for example) can utilize much smaller or let's say equilibrium amounts of CO2 and they still can build their mass (assuming other compounds like NPK etc are present) relatively quickly, while plants generally living in shadowed areas grow at much slower rate because they can utilize CO2 at much lower rates - and this is mainly because of lower energy coming from the light. Not to mention that many plants @Heelllooo keeps dont grow in shadowed areas in nature at all or their life there is rather miserable - not enough energy, while plants like anubias etc will lead happy life there.