Targeting Potassium

[MichaelJ]

There is always a fine line when using urea/ammonia.

Definitely. I personally believe it's been shown beyond reasonable doubt that urea/NH4 can trigger algae. Knowing what your doing - that's really the crux of the matter in my opinion... You can almost overdose NO3 to your heart's content... Not so with Urea/NH4.

Given the potency of these compounds I would urge that it is clearly specified under what conditions, and in what quantities it usually won't (or will) cause problems so we can learn something from this.

In my case, targeting 1 ppm of N from NH4NO3 in one of my relatively densely planted, moderately stocked low-tech tanks mentioned in #13 it seems to be perfectly safe and very effecient. How about 2 ppm, or 3 ppm ? I simply do not know.... If I used just NO3 ? I would bet the farmhouse that it wouldn't trigger any algae issues at all even at very elevated levels.


Cheers,
Michael

 

[hypnogogia]

Please, let me/us know on your results. I suppose you're going to see Fe and/or Mg deficiency symptoms.

How come, when EI is designed to ensure that fertiliser (both micro and macro) is not the limiting factor?

 

[Happi]

These pictures are from my experimental setups, you will find both good and bad results if you closely observe. 99% of the time I have used Ammonium or Urea as my main nitrogen sources.

NO3 is not exceptional either when it comes to causing algae issues. GDA was the most common algae when NO3 was dosed through KNO3 or when NO3 was present in high quantities.

NH4, Urea, KNO3 will all cause GDA and other types of algaes, some nitrogen sources might be more easily accessible or available to the algaes. Urea for example isn't easily available to the algae unless it's rapidly converted into NH4 and NO3. People who dose excess Urea are likely to see GDA and green algae formation on the leaves. This matter gets worse when soil is fairly new and leaching NH4 in the water and adding Urea or NH4 in excess amount on top of that is going to make things worse.

Occasionally, I managed to trigger green algae with the combination of CaNo3, MgNo3, KNo3 and Urea. But soon as I removed CaNo3, KNo3 and only kept MgNo3 and Urea in the mix, the algae goes away. I would except more algae to occur because MgNo3 and Urea mix contained more Urea. If I mix NH4NO3, Urea and KNO3, I would quite often see GDA and if I remove the KNO3 from the mix, the GDA goes away. If I only dose NH4NO3 or Urea in smaller doses, I almost never see any algae issues. if I dose KNO3 in larger quantities, GDA was covering the glass more often.

Nitrogen also needs several other nutrients to form algae, different algaes are form under differnt ratios and quantities of fertilizer or nutrients. Many people still believe that GSA is caused By low PO4, many people still believe that BGA is caused by low NO3, many people still believe that BBA is caused by low CO2. I debunked this in my own experimental setups on several occasions.

So what's the conclusion?

Does NO3 cause algae?
YES
Does Urea cause algae?
YES
Does NH4 cause algae?
YES
Does algae need other nutrients to form different types of algaes, including other Macronutrients and Micronutrients?
YES, Definitely
Does ratio and quantity of nutrients play any role in algae?
YES, Certainly

So, some people dose NO3, Urea or NH4 and still don't get any algae, what's the secret?
Because they know what they are doing.

 

[John q]

How come, when EI is designed to ensure that fertiliser (both micro and macro) is not the limiting factor?

Potassium can block the uptake of magnesium, I think the discussion here is at what ratio this happens.
@erwin123 summed it up.

K+ competes with Mg2+ for use of the non-specific ion transport channels

Tom barr was well aware of this problem and suggested a K:MG ratio of 4:1 not be exceeded, providing you had decent levels of mg.

Magnesium’s role in aquatic macrophyte nutrition - Volume 1, Issue 12 - December 2005

Barr Report Magnesium’s role in aquatic macrophyte nutrition

barrreport.com

What do I think the golden ratio is? I've no idea, mines about 2:1. K to Mg.

 

[Happi]

How come, when EI is designed to ensure that fertiliser (both micro and macro) is not the limiting factor?

Apparently people are still having nutrients deficiency.

 

[Hanuman]

So, some people dose NO3, Urea or NH4 and still don't get any algae, what's the secret?
Because they know what they are doing.

That sums it up pretty well and the reason why Tom Barr and many others have prioritized the use of NO3 because it's way more forgiving than urea/ammonia. Most people are not going to go down the rabbit hole of having experimental setups like you and Maq to make a point. You have much more leeway with NO3 than Urea/ammonia and does not require fine tuning everything making the experience of growing plant a pain in the butt, specially for beginners.

 

[_Maq_]

You would need to carry out your experiment in multiple conditions to definitely claim that urea has no effect on algae.

Quite the opposite, my friend. To prove that urea is the cause of algae YOU have to prove that upon any reasonable conditions, adding urea results is algae bloom. While ONE occasion when urea has no effect on algae is enough to say that urea is not the one and single cause, it HAS to be accompanied by other variables.

Also, it is documented that urea used in agriculture that leaches in water bodies can trigger algae blooms. Ammonia and nitrogenous waste are common triggers for algae. Nothing new there.

This is a field where I feel rather strong. I've read many papers on ecology of water systems. There's no doubt that increased levels of nitrogen are the source of algae infestation. However, I've never seen a paper documenting that urea or ammonium are harmful while nitrates ARE NOT.
In short, your argument is valid for nitrogen but says nothing on its form (organic, urea, ammonium, nitrates).
(By the way, it's quite a mystery to me why nitrates in amounts faaaar exceeding anything known from nature are not disastrous in our tanks. It shows, at least, than not all that we can observe in nature can be directly applied to our hobby.)

Fish don't all pee and exude excrements at the same time.

Fish permanently exude ammonia through their gills. Fish tank without ammonia is inconceivable.

 

[John q]

While ONE occasion when urea has no effect on algae is enough to say that urea is not the one and single cause, it HAS to be accompanied by other variables.

So going back to the op's question. If we can find one tank with much higher potassium levels than magnesium and beautiful plant growth, does this disprove the K:Mg ratio argument.

Gotta play devils advocate here @_Maq_

 

[_Maq_]

Here you can see the mineralization:

The experiment was targeted at K:Mg:Ca ratios. The tank C was aimed at emulating "average Barr". The tank D was pretty the same, except half of the nitrogen was dosed in ammonium form. Please note, quite a lot of ammonium!
Here you can compare the tanks after 121 days running the experiment. Let me assure you that during whole period, algae infestation was never better nor worse in any of the tanks:

Hygrophila corymbosa showed quite nicely what excess potassium looks like:

 

[_Maq_]

If we can find one tank with much higher potassium levels than magnesium and beautiful plant growth, does this disprove the K:Mg ratio argument.

In this case, we'd had to relate to individual species.
If we find one species which performs badly in given ratio, then we must keep on searching and dismiss that ratio as "ideal". Frankly, I'm still searching for a perfect ratio (and not sure whether a ratio fitting ALL species even exists!) But I've already dismissed some obviously wrong ratios. Par example, whenever there's more K than Mg, it's definitely wrong.
(But yes, you're correct, I'm a lawyer by original profession. But please, don't be a "populist" in suggesting that lawyers tend to transform the truth in a creative way. Rather, lawyers are trained in judging what forms a proof and what does not.)

 

[Oldguy]

In this case, we'd had to relate to individual species.

Interesting. I do not think there is an ideal anything for a very mixed planting.
Old timer books talk about groups of plants that are compatible and others that are not.
I an coming round to the view that the K:Mg ratio may be key to the Hydrophila family, though it is a large and plastic group. It is easy to assume that as many are fast growers that there is 'just' a general shortage of nutrients when leaves start to pin hole or show other problems while other plants in the same tank are growing well.
It would be very informative if the commercial growers could shed some light, though their growing beds are fish and critter free.
As ever more questions than answers.

 

[dw1305]

Hi all,

Nitrogen also needs several other nutrients to form algae, different algaes are form under differnt ratios and quantities of fertilizer or nutrients. Many people still believe that GSA is caused By low PO4, many people still believe that BGA is caused by low NO3, many people still believe that BBA is caused by low CO2. I debunked this in my own experimental setups on several occasions.

So what's the conclusion?

Does NO3 cause algae?
YES
Does Urea cause algae?
YES
Does NH4 cause algae?
YES
Does algae need other nutrients to form different types of algaes, including other Macronutrients and Macronutrients?
YES, Definitely
Does ratio and quantity of nutrients play any role in algae?
YES, Certainly

Personally I'm sure you are right, I'm not sure that the <"form that you supply fixed nitrogen in"> really matters.

There are plants (in the widest sense of <"photosynthetic organisms">) that occur in all the <"possible combinations of conditions">.

I've <"always had problems"> with the <"plants you want and the plants you don't want, but they are all plants"> conundrum. If it's <"sauce for the goose, why isn't sauce for the gander">?*

*for @Hufsa

Cheers Darrel

 

[_Maq_]

I'm not sure that the <"form that you supply fixed nitrogen in"> really matters.

I think you referred to algae. Nevertheless... If you look closely at the pics I've posted in #29, you can see that Mayaca and Tonina suffer in the tank C, which contains no ammonium.
You can also see that Rotala wallichii got stunted in tanks C a D - with wrong "Barr-like" K:Mg:Ca ratio.
These three species are often considered demanding. In my tanks, they grow literally like a weed. I think that dosing ammonium, and not overdosing potassium makes the difference.

 

[dw1305]

Hi all,

Nevertheless... If you look closely at the pics I've posted in #29, you can see that Mayaca and Tonina suffer in the tank C, which contains no ammonium.

These are really interesting experiments. Tank B is doing amazingly well, just on <"petrol fumes">.

cheers Darrel

 

[MichaelJ]

So, some people dose NO3, Urea or NH4 and still don't get any algae, what's the secret?
Because they know what they are doing.

I don't know what I am doing, I just ask you

Cheers,
Michael

 

[Happi]

I don't know what I am doing, I just ask you

Cheers,
Michael

You must be doing something right if algae hasn't occurred while using Ammonium based product.

 

[MichaelJ]

You must be doing something right if algae hasn't occurred while using Ammonium based product.

Yes, and that right is that I follow your dosing recommendation for my low-tech of 1 ppm of N with Specialized ... no sure what would happen if I would go rouge and dose say 3 ppm...

Cheers,
Michael

 

[plantnoobdude]

Yes, and that right is that I follow your dosing recommendation for my low-tech of 1 ppm of N with Specialized ... no sure what would happen if I would go rouge and dose say 3 ppm...

Cheers,
Michael

Still too much... Go LEANER

 

[MichaelJ]

Still too much... Go LEANER

haha ... Keep in mind though that the 1 ppm of N is only dosed once every 11-12 days after I do the 35% WC. So if you break it down to weekly its really only 0.58 ppm/week. P is 0.046 ppm/wk , Fe is 0.032 ppm/wk.... not sure what crazy mind trick you guys have been pulling on me, but apparently it works... for 10 months now

Cheers,
Michael

 

[plantnoobdude]

haha ... Keep in mind though that the 1 ppm of N is only dosed once every 11-12 days after I do the 35% WC. So if you break it down to weekly its really only 0.58 ppm/week. P is 0.046 ppm/wk , Fe is 0.032 ppm/wk.... not sure what crazy mind trick you guys have been pulling on me, but apparently it works... for 10 months now

Cheers,
Michael

Pftttt basically EI...

Jokes aside, glad to hear it's been stable long term in your tank.