Alternathera reinekii problem

[FishRocker]

Leaves on my A.R. are stunted and crinkled looking, please help !

30gallon
2x65 pc lighting on for 9 hours
Eco-complete and flourite mix for substrate
Co2 @30ppm
EI ferts w/50% weekly water change

 

[defdac]

It helped me and a couple of others to go down in PMDD dosing, particulary NO3 and PO4. When I dose more than 10 ppm NO3 via KNO3 per week (50% wc each week) I get crinkled leaves.

Seems that when some plants have their metabolism going super-fast via high light/high CO2/high nutrients the calcium allocation can't keep up or something.

High lignin plants like A. reineckii and L. glandulosa seems particulary affected by high growth rates, maybe because of this: "The status and the cation exchange capacity of the apoplast are particularly important for Ca uptake, because Ca must move entirely through the apoplast to the xylem. In the apoplast the cation exchange capacity of the cell wall is influenced by the relative concentration of the
cellulose, hemicelluloses, and lignin, which can vary greatly between plant species, and can have an important influence on the absorption of specific
ions."

and this:

"Dicots need more Ca than monocots, which has been attributed to a larger cation
exchange capacity of their cell walls."

 

[Tom Barr]

I've never had issues with high NO3/PO4 and L granulosua.
I've seen A reineckii much more often, but it's with folks that have high light.
Few folks ever had such issues until they added high light.

Here's the client's tank using EI and less light without issue:

He has never had curling leaves with high PO4 and NO3.

While lowering some folk's tanks with NO3/PO4 has solved their problem, it obviously cannot be the reason "why" the plant does not do well of exhibits those attributes.

That's impossible.

It actually was the reason "why", then adding it in every case would show those symptoms.

That much is clear.

Now if you have tried a few things and cannot get decent growth etc, there is a temptation to suggest it's high PO4/NO3.

However, you alone(or a small group of "me too's") are not the only one's out there growing this plant.

All it takes is one good falsification to disprove the hypothesis put forth.

This client has been using EI for a year. The L granulosus is his favorite red plant.
He has grown massive amounts of it.
I have as well going back over a decade.
A reineckii ever longer.........

I'm not saying what the cause is, I am saying what it cannot possibly be.
There may be secondary issues caused by adding NO3/PO4 that are not present in the above tank's example, eg too much light for a given CO2 level.

There are many red plants that are far pickier than A reineckii, this has always been considered one of the easiest "red" plants around going back 20 years.

The pickier plants also have no issues.
Often, when a plant stunts, it takes a while to recover. Ammannia gracilus etc is like that, but A reineckii rapidly regrows side shoots. I've had really super bushy side shoots from topping. Such growth and responses to pruning/topping is why is was used so much in the past.

Give it some shade, some more CO2 and some patience.
Plants need far more Carbon than they do Ca and Ca is at the site of new growth, the plant is submersed, so there's little need to transport if the plant can take it in through the leaves. I'm not sure that this plant(or a lot of the plant species we keep can indeed do this vs the roots. But the research suggest based on other aquatic plants, that they do.

Even so, a simple test of the hypothesis that EI or higher levels of NO3/PO4 cause problems shows that something else is going on if you have issues.

You cannot suggest that you have answered the cause based on the data.
It just does not support your conclusion.

Regards,
Tom Barr

 

[Tom Barr]

Another example using EI:

2003 AGA International Aquascaping Contest

Plenty of so called hard to grow red plants.
James had 8 months total in the hobby when he did this tank.
Not bad.......

Regards,
Tom Barr

 

[defdac]

Low NO3/PO4 seems to be the key for some people that always get this plant curly. You havn't proven why that is by saying that you can grow the plant under some special conditions that noone else knows.

That is like saying noone are having trouble with this plant. High NO3, PO4, CO2 and light is easy - and often a necessetiy to grow the pickier plants (none of the plants in the screenshot you provided).

However under certain conditions this fails with A. reineckii and L. glandulosa for example. Conditions you do not know.

Let's setup a test to see why folks are having trouble instead of saying "100 people can grow this plant so you should too".

My tap and moderate lighting with EI and good CO2 is the premises. I can get this plant to get curly by only changing the PMDD part, so let's find out what is going wrong.

 

[Tom Barr]

I do not have to prove why someone else has issues, only why the hypothesis put forth is wrong and cannot possibly be true.

I'm not trying to prove what it is, I just proving what it is not.

That way I scratch off one issue as not a cause and not waste the time looking there for a solution. I can also prove PO4 excess does not cause algae, but that does not say what does cause algae.

After you are able to confidently rule out each possible cause, step by step, you often are left with one or two hypothesis that you cannot rule out.

Often, those are the "causes", until you are able to disprove them and find out some alternative cause.

This plant has a very long history in the hobby.
I've seen the curly stunted tips in other folk's tanks.

I have no "special conditions", magic water etc..........even if I did, there's some other limiting condition if your tank if the high NO3/PO4 in mine does not stunt the plant. You cannot argue or ignore that point.

No one can solve every possible issue for every person's tank on the web.
But we can rule things out by testing them.

In order to test anything with plants, you must provide non limiting conditions for the other independent parameters and then vary the dependent parameters. This is basic plant science if you want to test nutrients limiting/ inhibiting excess.

If you want pickier plants at even higher nutrient levels:

This was a weed farm.
EI dosing as well.

I'm not saying folks are not having troubles with this plant, or any plant for that matter....... merely because I can grow it at high NO3/PO4 conditions.
I'm just saying that at high PO4/NO3, that cannot be the direct cause for this plant and for this expression of growth(or lack thereof).


That's what a test is.
I do not think you have the concept to set up the test.
1.You make a hypothesis
2. You set a test that reasonably can disprove that hypothesis.
3. you do the test and see. You do it again, 5-6 times perhaps.
4. You do the test on purpose, not just happenchance observations as you try to improve the growth of your plants.
5. You set up non limiting conditions
6. Make sure things like basic aquarium keeping are addressed, good flow/current, clean filters, heater,
7. Stable acclimated growth before the test starts..........this one is hard for anyone suffering from poor growth, but using a stunted plant to test anything is a bad idea..............

#7 is part of the problem.
You cannot solve much if you cannot grow the plant to start with well.

Even though I can grow it, the person having troubles seems to think I must be wrong in their frustration.

However, they are not thinking clearly.

Neither of which is my fault nor has a hill of beans to do with me

If they really want to learn, then they should use a good method to prove things to themselves and not just believe everything they or others think.
That's why Science works so well.

It's a slower process, but you learn a lot more.

I have several test running now, I do not have the time to test every issue every person might have.

I might get some of this plant again and start growing it, but like the older claims of the past(PO4, K+ inhibitions, trace metal blocking etc etc), I already have a long time's worth of growing experience with this specific species, I have plenty of examples of the plant being grown well under EI.

And not just myself, but dozens of folks with this plant.

The other alternative is that we are all lying, but the conspiracy would be tough to pull off

IME, the folk's tanks that have resolved things and done well simply reduced the light and added more CO2. You can move the plant to rear of the tank etc. Many examples have the plant in the BACK GROUND. People think red plants require high light, this is not true and I can show this in tanks and in the field/natural systems.

If you reduce the NO3/PO4 to a limiting level, that will reduce growth rates. If you add more NO3/PO4, then CO2 can become limiting.

PO4 might be very limiting @ 50ppb, moderately limiting at 200ppb and totally non limiting at 2000ppb.

The degree of limitation is not black and white.
If you add in the rate of dosing such that PO4 is 200ppb, then you will have much less CO2 demand by the the plant vs 2000ppb.

Plants will still grow, perhaps even nicely, but at a reduced growth rate and at a much reduced CO2 demand.

However, this is confounded experiment if you do not have non limiting CO2 for each case of PO4 treatments(as well as other parameters). I think many have non limiting CO2 at say 200ppb, but not at 2000ppb PO4.

That's why they see the lower levels as adequate(at least one possible reason-there may be more/others) and "the cause", it's causing limitation and downregulation of CO2 demand when they add less and upregulation leading to limitation(temporary perhaps, causes some stunting) when they add more. It takes a few days for the plant to reorganize and respond, many aquarist are not that patient nor willing to risk more bad growth just to test things.

Regards,

Tom Barr

 

[Tom Barr]

Defdac,

I do understand where you are coming from and the skepticism.
In light of that, I am going to do the test in detail for you and other folks.
Even so, in doing this, other folks may still not believe me

However, working with one plant in isolation, should help.
I will make several hypothesis, then try and attempt to disprove each one and provide a photo of a purposely induced deficiency(or lack thereof).

Regards,
Tom Barr

 

[VaughnH]

Defdac,

I do understand where you are coming from and the skepticism.
In light of that, I am going to do the test in detail for you and other folks.
Even so, in doing this, other folks may still not believe me

However, working with one plant in isolation, should help.
I will make several hypothesis, then try and attempt to disprove each one and provide a photo of a purposely induced deficiency(or lack thereof).

Regards,
Tom Barr

This will be very interesting - worthy of a "special edition" of the newsletter - "The Alternanthera Chronicles"?

 

[Tom Barr]

Yes Vaughn, at some point you are motivated to actually answer the question yourself and do something about it. Guessing never cut it for me, I question everything, and then attack myself as well later.

Gerloff and Krombholz(yes, Paul K., the same Guy on the APD, but back when he was a young guy!) did many such studies in the 1960's with such nutrients.
Other's have done similar studies since and looked at seasonal difference in nutrient uptake etc. This is research and news has been around for 40 years but aquarist for some reason still go to the myths. Be careful not to believe everything you think. They did not however, look at A reineckii, a very common "red" plant for many back in the 1990's.

I don't believe myself anymore than I believe the earth is flat......., I test it and set up a good experimental design to see.

Then repeat, then try and induce the issue-this step is important at getting at causation......(say stunted tips in A reineckii) with the said hypothesis(say adding progressively more and more NO3, say (5ppm, 10ppm, 20ppm, 80ppm).

I've never been able to do it in the past with a pair of tanks, but I know how to set up a reasonable test to prove that it is/is not due to NO3 dosing.

What test do you have that can disprove the hypothesis or confirm it may be "tentatively" true/possible?

You also have to be able to grow the plant well to have good starting and control conditions. Many do not have that.

Due to this thread, and several others over the last few months, years, I'm going to do this experiment with A reineckii again, it's been 8-9 years now. I want to do a complete test this time.
I did this with Ammannia and K+/Ca++ blocking 5 years ago.

It'll be a few weeks, but It should be fairly easy to prove correct/incorrect, that high NO3 will induce stunting in this plant.

I'll use ADA AS and also plain Sand.

The tanks are small, 3 gal, I have 8 of them so we can do 2 replicates of 4 NO3 concentrations. No fish etc, so I can add lots of CO2 to ensure on limiting CO2, as well as PO4,Ca, Mg, Traces etc. I can also measure light evenly in micromoles.
I have mainly shop lights but can get them to about 150-200micromols since the tanks are shallow.

I can measure Dry weight changes in growth as well between treatments and take photos. I could also see what the N, Fe and P in the tissue is before and after also. That will cost a little.

Takes awhile, but it's not that hard to do.
Few aquarist will bother and thus the myth will live on.........till someone comes along and kills the sucker.

While I do get in disagreements with aquarist, I also do test and show and prove my contentions. I rarely get the same back however. I find that unfortunate, as many can be tested if they discuss the test methods, look up the research that's been done and ask.

There is a great deal of things an average planted aqurist can do if they try.
I detail things out and discuss all this for a reason, hopefully someone will come back and set up the test again for a different plant, or another question and are able to answer it well having had someone before them show a simple method.



Regards,
Tom Barr

 

[naman]

Once I have found this paper:
John Skok "Effect of the form of the avalable nitrogen on the calcium deficiency symptoms in the bean plant", and it seems like
kekon’s assumptions in How to balance NPK, Ca, Mg and micros - new experiments partially wrong.

John tested plants with Ca deficiency -Ca and CO(NH2)2 dosing VS. -Ca and NO3 dosing. I allow myself to quote:

«Calcium has been found to be one of the most important mineral elements needed for normal plant growth. In its absence plants exhibit very severe deficiency symptoms.»
«The reason that calcium deficiency has a more severe effect on a plant than the deficiency of almost any other single element is probably in part because calcium has been found to have many functions in growth and development.»
«If minus calcium plants lose their capacity to reduce nitrates and synthesize proteins, they are essentially minus nitrogen as well as minus calcium.»
«(1) Under normal conditions including the presence of calcium, urea is not as good a source of nitrogen as is the nitrate form for growth of the bean plant.
2) In the absence of calcium much better growth is made
by the bean plant with urea than with nitrates.»
«The form of the available nitrogen, however, has a very pronounced effect on the calcium deficiency symptoms. With urea, the calcium deficiency symptoms are much delayed and when they become evident they are very much less severe.»
“...calcium deficient plants have a lowered reductase activity since the calcium deficient plants receiving urea, which is a reduced form of nitrogen, make much better growth than do those receiving nitrates. The calcium-deficiency symptoms of the plants receiving urea, then, are really truer symptoms which can be directly assigned to the lack of calcium. Since other elements, namely potassium, phosphorus, and sulphur, were also found to be necessary for normal reductase activity by ECKERSON (3), it may be entirely possibly that their deficiency symptoms may also be lessened in severity with the use of urea.”​

So there is no NO3/PO4 “overdosing” in very soft water.

Plants assimilate NO3 reducing it to NO2, than to NH2 and only than “eat” it up.
When Ca is in deficit plants just can’t assimilate NO3 at needed rates because they have big problems with reducing ability of NO3, so really it is not “overdosing” NO3, but general lack of N !
NH2 (urea, amino acids, guanidine nitrate) cures N deficiency of plants coused by lack of Ca giving them reduced form of nirogen, but again not the couse itself – lack of Ca.

As Tom advises lowering growth rates by lowering light intensity, or as someone may say lowering NO3/PO4 dosing to some degree cures simptoms, but again not the cause itself – lack of Ca/Mg.

So, overdosing of B and underdosing of Cu is not the case with such simptoms?
Lack of Cu at very low GH coused by lack of Ca, and intoxication with Boron is caused by lack of Mg.
Or we still have to dose TMG to fix the issue?
I see that Tom Barr is totally right that TMG helps because it has lowered level of B and elevated levels of Cu, so we can say TMG is “tuned” for soft water and effectively prevents mentioned disorders, while PMDD on Plantex CSM+B is not?

Give to tricky plants a little bit of shade (or shorter lighting peak)
keep GH not less than 4-6 dosing GH booster etc or mixing RO-water with tap water 1:4
give some part of N in amidic form
dose TMG or equal (less B, more Cu) instead of PMDD or equal
....and enjoy very fast growth rates with RO-water without any leaves distortion.


It is my understanding only.
Correct me if I am wrong, please.

naman

 

[Tom Barr]

Well, that test is from 1941

I think that's a bit dated, however, unless we find a refute or an issue, it may be hard to say. It's for beans, not aquatic plants.

I critiqued Kekon's results and test. The data does not support the conclusions.
Other might think so. They are welcomed to try

If you cannot critically measure light and CO2, then things are going to be tough to argue. I've been very anal for the last few years about CO2.
I am never quite certain how accurate I am, until very recently.
Several methods have converged to get very accurate measurements.
None of which any aquarist is doing.
I've not met a single planted tank aquarist that even uses a PAR light meter, or Globe type light probe etc.

How can talk about 1 item like Nutrients, without addressing Light and CO2?
CO2 levels can and do change, flow and current influences this and nutrient uptake as well via the boundary layers.


I have the plants coming and they will be here Friday.

So I can clearly show that they grow like weeds at high NO3. If my client can do it with all the issues he's had, I know I can I have grown this plant for years in the past and for other clients off and on.

Always an easy plant for me.

The tap here has 0.0 ppm of NO3, sierra snow melt, so 3 x 80% weekly water changes with 20ppm will be dosed. I have items at the lab where I can do this also, but have not got the CO2 set up just yet.

But all I need to do is make certain CO2 and current are not limiting, that's easy to do for me.

Light is easy to measure for me.

And adding 20ppm NO3 3 x each week ought to be able to show high levels of NO3's impact on this specific plant and put this issue to rest.

3x week 80% water changes will also make my tank look better and help me garden a bit more too. I'll have extra to swap at the meet and also add to another client's tank to change things around.

Further, I bet I can induce the stunted tips using CO2 while maintaining stable NO3.

How ya like them apples?
Why?

I've already seen this several times with this plant.
Inducing it with CO2 while stable high nutrient levels shows at least one cause, however, there may be others.

Still, if it's not able to be done with high NO3, then we can say that NO3 at 20-30ppm is not the root cause.

This is the principle of falsification.

I've long played with these ratios and levels going back many years now.
This is old Hat, but I can redo it again and show it and prove it. It's not hard to set up the test, having done it many times already.

Some of the folks claiming such relationships to be true might be mythed by this, but it's not personal, it drives at the very core of learning, rather than accepting belief.

You test the issue, then if it does not induce the response, you try the next best alternative. You keep going and you make sure things are doine correctly over the time scale of the test.

Some just want to analyze everything with a little ferts here or there on their tank rather than set up and really monitor a real test. Further, fewer are willing to test what induces stunting, all they want to do is get rid of it.

I'm not that way, I want to know why and am willing to take risk to learn.
This is the only real way at looking at causes(at least one possible cause).
I did this with algae and found and learned a great deal where others had a mere crude understanding prior.

Having won the algae debate and it's now well accepted, the next stage is stunted tips and other potential issues with growth patterns.

Folks still get algae and have high PO4 in some cases, but most folks would not argue high PO4 = algae these days. 10 years ago they did aggressively.

But like then, when you add the fertilizer to the tank and you only get more weeds and nice growth, what else can you say when someone suggest high NO3 = stunted plants and you know you have those conditions and there's no poor stunted tip growth?

Same deal with PO4, of high K+ blocking Ca or fish toxicity etc etc.
You test and see. But you need to test and design the test to answer the question.



regards,
Tom Barr

 

[Tom Barr]

Blackwell Synergy - Freshwater Biol, Volume 6 Issue 2 Page 145-154, April 1976 (Article Abstract)

Think about this paper, the NH4 is removed via the leaves first and most of it comes through that pathway.

Think this plays a role?
Algae?

How about growth rates with N and adding CO2?
SpringerLink - Journal Article

Do you think 21-24X more biomass will require more N?

Does more N drive more carbon demand in plants?

Nitrogen and Carbon Nutrient and Metabolite Signaling in Plants -- Coruzzi and Bush 125 (1): 61 -- PLANT PHYSIOLOGY

Given such tight linkage between NO3 and Carbon, I do not see how they cannot be linked.

Aquatic plants can be drastically limited by CO2 inside of 1 hour or less at teh on set of photosynthesis. Rubisco levels are altered to try and scavenge every bit of Carbon available in the exterernal environment, however, short term decreases are used from carbohydrate sugar pools in plant cells.

They basically eat themselves trying to make do until they get more Carbon to work with. What choice do they have?
None really.

It takes time for the plants to adapt to a given CO2 level, they will take a week or two in most cases. Once Rubisco levels stabilize, then things go pretty well.

But if the Rubsico and CO2 demand is all over and the supply variable, this situation makes it difficult for the plant to respond.
Adding non limiting NO3 can drive Carbon demand higher also.

So if you add non limiting NO3, you also must ensure non limiting CO2 and other nutrients.

If not, you get stunting, slower growth etc.
In some plants, folks like the slower growth, it's not an eye sore, in others, it can cause issues such as this one.

Also, many folks have a lot of light and want the plants to grow faster(I guess that's why they have high light), reducing light also resolves many such stunting issues as well.

Light drives CO2 demand also, less light= less CO2 demand, less nutrient demand.

So if I can induce this with higher light and with CO2, maybe it's not really the NO3 at 20ppm?

You will note, many folks often consider this plant a good red plant for low light and it's often seen in the rear of many tank displays where there is lower light.
You can also view it growing well in a non CO2 tank, I've grown it in the past in such a non CO2 tank as well here:

zero water change 20 and a 75 - *UPDATE 56k hehe* - The Planted Tank Forum
there's some in here, not the best example, but it does grow pretty in such tanks.



Regards,
Tom Barr

 

[naman]

Thank You,

At THIS time I see the answer is: "Wait for results of tests"

but I have a feeling that my understanding was right, even with data of 1941 on bean plant.

Waiting and keeping silence...

naman

 

[Tom Barr]

Well, the old stuff often is done well, but sometimes they do have things they over look.

At the luxury uptake stuff is likely in error because the test where only done for 3-6 weeks etc, not an entire season, plants use the excess stored nutrients for many things in the season that you'd miss in the shorter nutrient uptake studies.

Regards,
Tom Barr

 

[detlef]

Still, if it's not able to be done with high NO3, then we can say that NO3 at 20-30ppm is not the root cause.

Referencing the paper from 1941 on a terrestrial bean plant Kekon claimed that he found the reason for stunting on some SAMs --> High NO3 (20ppm) A N D Low GH (2-3 degrees). Well, we already know that NO3 levels around 20-30ppm ALONE does not stunt plants!

The question should be answered whether there is or is not a particular ratio of NO3 to Ca/Mg which can lead to stunting. You previously said that you've grown A.R. in high NO3/PO4 water without issues. Which GH and KH levels have you maintained at that time?




Also, other than for high biomass production I don't see why you want to set up the test with 3x 80% weekly wc's and 20ppm NO3 dosing thereafter?

Best regards,
Detlef

 

[Sintei]

I'm SO looking forward to your test results!

 

[Tom Barr]

The Gh is the client's tank I just got back from, was 2 degree's, a tad less, the A. reineckii is 3ft tall before I hacked it back and he has been running fairly low light.

I have low GH here, about 2, the KH is 1, I add maybe 1/4 teaspoon of GH booster per 80 liters once a week at most..........KNO3, pretty juicy.

High light.

I have not set the test up yet.

But I do not think based on the tap, GH/NO3 ratios, when I've grown the plant in the past, and with the client's tanks, I buy Kevon's rational for one minute.

I read that some time ago.
I still do not buy it.

GH alone is another issue, Ca or Mg?

Low Mg can cause issues and if you assume GH = a good ppm of BOTH Mg and Ca, then ..........well...........I do not think it's low Ca.
Mg maybe, but I do not think divalents will cause this.

What I do think, folks get down to such little ppm's , they have poor test kits, .methods, forget, do not pay attention, get lazy with testing, poor CO2, many possible things, and assume it's cause.......

I thought the original premise here was high NO3?
Now it's low GH and high NO3?
How about high light, low/moderate CO2, and low GH?
We can add more and more complexity and really confuse the test and the results.

I have high nutrients in my sediments as well as the water column.
I have had those ranges, without issue with this plant.

The plants are growing out now.
So we will do it again.

I can make many mistakes, so can Kevon, however, if I can make one test right to show my hypothesis, the null, is correct, then I've shown their's is not possible under the assumed conditions.

So one positive case where I have low GH, high NO3 in these ranges shows that cannot be correct.

Regards,
Tom Barr


Regards,
Tom Barr

 

[defdac]

My predictions of the outcome of a test:

The tips will curl if you maximize the growth rates with high CO2 and high light and high nutrients and have a plain gravel substrate without nutrients, possibly also low (

 

[Tom Barr]

You maybe right.

I got back from LA this weekend and found this client loves L granulosus(has maybe 100 plants at pretty deep depths, 1.2 meters) and about 30 A reineckii.


He uses Eco Complete(had ADA AS, I removed it) which is fairly inert other than a source of Fe and perhaps Mn.

He does 50-60% weekly water changes, sometimes more, using a 700 gallon RO water reserve. He adds a little tap KH, maybe 1 degree.
He does add MgSO4.

These two species get tall and have good color.

Sand vs EC?
Perhaps.

I will not suggest that sand and EC are identical, nor suggest that EC and ADA AS are either.

His tank does very well, but it's more a lower light tank now, we had the MH's screened off to reduce intensity about 4x less now.

I have a new 130w PC light and a grow out 20gal/80 liter 60cm long tank here.
I'm bringing back some Anubias and a few other plants and have the A reineckii in there with ADA AS.

I can add plain sand though, I just take a pot fill it with sand and add it in there.
Add a bit of mulm.

You can do/use pot sediment test like this in a single tank, although some water column -sediment interactions do/can/perhaps take place and these cannot be ruled out using this method.
But.....you can justify the water column issues by having non limiting nutrient levels such as NO3 while not adding Ca/Mg.

SF bay area has notoriously low GH and KH, it's all glacier snow melt into granite water sheds with low organic matter. Flourite etc was not popular until the 2000's and we grew these plants as well, many folks had GH's of 3-4. We did have to add some GH booster, via SeaChem Eq, or some of us had different tap, like myself.

It might be more to do with too low Ca and Mg rather than high NO3.

The high light + CO2 + NO3 might drive growth too fast to keep up with nice foliage under certain GH limiting conditions.

I would not argue against that, there are limits.
But it's not just "NO3 causing stunting", that's wrong.
More like, the low Ca and Mg are causing the stunting, if you limit say Light or CO2, or NO3, then that switches the limiting nutrient to NO3.......not Mg or Ca.

Kevon implies NO3 at 20ppm is bad for some plants and that's just not true.
That's what folks read, that's what folks say and claim and have for about 20 years in this hobby and it's just not true.

Anyway, if you have a pair of sediments and one does does with a plant and the other with the same plant does not with non limiting nutrient levels, that might suggest something else is occurring in the sediment.

I can set the test up and will this week.
Sand, ADA, Flourite sediments, in the 80- liter tank, no fish, lots of CO2 mist, light, I'll do 2x a week water changes and dose 25ppm each time NO3 as well as 1 degree of GH extra to get to 3GH.

Traces, PO4, K+ etc.

Then you can look after a few week's growth.
The 2x a week flushing ought to remove a lot of the sediment water column interactions also.



Regards,
Tom Barr

 

[growitnow]

plant ID in Tom's client tank

Hi,

Can someone ID the (stringy tentacle-like) plant clumped en masse to the right of the driftwood pillar?

Thanks