Form of NH4/NH3 relative to good/poor CO2 concentration

Tom Barr

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This idea is from this paper:
https://link.springer.com/article/10.1007/BF01049799?LI=true

While aquarist do not keep rice and do not add Triazine herbicides, I wonder how the effects of NH3 vs NH4 plays when the CO2 is poor.

Poor CO2 leads to many disasters in planted aquariums. But is it solely due to the CO2?
Perhaps, but the ratio of NH4 to NH3 is determined by pH and new tanks tend to have ample NH4/NH3 and that's also when it's most likely to get algae.

Seems poor CO2 will raise the pH and produce MORE NH3, less NH4.
At lower pH's, eg softer tank water, ample wood and tannins, peat etc, you do see some correlation with less algae and easier start ups.

When we add say a Jobe's stick to a planted tank in the water, we generally get some algae bloom.
When we add ADA AS additions, we rarely do.

One adds peat and binds the water hardness, both add plenty of NH4/NH3.
This is not a cut and dry scenario. Uprooting Jobe's sticks has caused many headaches and algae blooms for many, yet we see much less issue, when we use ADA AS.

I'm not sure if it's pH related, but it would explain why poor CO2 and NH3 can cause problems together.
If the CO2 is richer, then the pH will be lower. If the water is lower KH, then the pH will also be lower.
If peat is added, the pH will be lower and the KH will be lower.

In non CO2 systems, if the water is not changed, then the KH will be lower so will the pH.
 
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Allwissend

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This idea is from this paper:
https://link.springer.com/article/10.1007/BF01049799?LI=true

While aquarist do not keep rice and do not add Triazine herbicides, I wonder how the effects of NH3 vs NH4 plays when the CO2 is poor.

Poor CO2 leads to many disasters in planted aquariums. But is it solely due to the CO2?
Perhaps, but the ratio of NH4 to NH3 is determined by pH and new tanks tend to have ample NH4/NH3 and that's also when it's most likely to get algae.

Seems poor CO2 will raise the pH and produce MORE NH3, less NH4.
At lower pH's, eg softer tank water, ample wood and tannins, peat etc, you do see some correlation with less algae and easier start ups.

When we add say a Jobe's stick to a planted tank in the water, we generally get some algae bloom.
When we add ADA AS additions, we rarely do.

One adds peat and binds the water hardness, both add plenty of NH4/NH3.

I'm not sure if it's pH related, but it would explain why poor CO2 and NH3 can cause problems together.

If I understand correctly, your hypothesis is that high pH(>7) caused by low CO2 combined with the presence of NH3 cause more problems regarding algae than the same concentration of NH4 at a lower pH. Furthermore, as most KH binding substrates indirectly lower the pH, they act as a protective factor even though they are a source of NH3

My question is:
Are algae unable to use NH4 just as well as NH3? Are plants any different?

A quick look at the abstract reveals this:
"As pH rises the potential loss increases exponentially due to the increasing dominance of volatile NH3 gas in equilibrium with NH4"

So the main concern of the authors was loss of NH3 from the solution as NH3 escapes in gas form . When the aquarium has a higher pH you loose more of the produced /added NH3 through off-gassing.


In non CO2 systems, if the water is not changed, then the KH will be lower so will the pH.

I wish the effect would be stronger... With a Kh of 17 °dGH from tap in some areas, it will take years to get the pH under 7 due to KH drop alone.
 
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tiger15

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Isn’t the paper refers to algae suspended in water column, not algae that stick to plants in aquarium. There are many types of algae, and the causative factors are different.
 

Tom Barr

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Isn’t the paper refers to algae suspended in water column, not algae that stick to plants in aquarium. There are many types of algae, and the causative factors are different.

Periphyton is different true, but there's an absence of research regarding NH3/NH4 and pH.
However, Green water (Phytoplankton) and NH3 do seem correlated, new planted tanks tend to get Green water or if the sediment is disturbed a great deal. If they use ADA AS, which lowers KH, via peat and clay binding sites, you do not get green water. Older ADA aqua soil seems more prone to getting green water as well.
The zoospores of Green Dust algae seem to respond to this but it's more subtle.
We see fewer issues adding NH4 at lower pH's. Meaning less periphyton and phytoplankton.

Can we say that NH4 causes algae? No, this has been falsified: e.g. there's dependencies.

I'm not saying that this paper proves anything, I'm saying it's general idea may support the and provide a working mechanism for periphyton/phytoplankton in planted tanks.
We know NH3 is more toxic to most all life at higher pH (higher KH/alk and/or lower CO2).

http://www.thekrib.com/Chemistry/ammonia-toxicity.html

Example, at 2.0 ppm of NH3 added to water with a temp of 25C, pH of 5.7, you only have 0.0006 ppm as free ammonia, the rest is NH4+.
The same conditions at say 7.0 is 0.0115. I am not certain if the CO2 addition changes the ratio of NH4/NH3. I do suspect that it does.
A 1 pH change daily has little impact of fish, CO2 is not a salt. Algae do not seem to respond to it either.

But perhaps the algae need light cocurrently. More light, warmer temps, new tank, inorganic plain sand, poor CO2.....good way to get algae generally, but why specifically?
Temps okay, but warmer temps= more unionized NH3.
Peat, clay soils= bind alkalinity, pH drops.
Poor CO2, pH drops but not as much, plants do not do as well cocurrently.
New tank, little bacterial action on NH3/NH4.
Plants: poor CO2: less uptake of NH4.
High light: easy for algae spores to germinate.

I do not think this is a key, but adds to the larger picture.
 

Tom Barr

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My question is:
Are algae unable to use NH4 just as well as NH3? Are plants any different?

They are equal in vegetative growth, but our plants are not germinating, eg, from seeds. Algal spores do germinate and often require a trigger or host of triggers mostly.
Algae can have several life stages. GDA is but one of that alga's life stage as motile zoospores. You wipe the little devils off the glass, an hour or two later, they are back on the glass.
People thought it grew right back, but they were just swimming around after being wiped off the glass and then reattached to the glass again. If you leave them be for 3-4 weeks(hard to do due to the green film on your tank), they finish that life stage and move on to the next one. This worked for many, did not for others.

So the main concern of the authors was loss of NH3 from the solution as NH3 escapes in gas form . When the aquarium has a higher pH you loose more of the produced /added NH3 through off-gassing.
I wish the effect would be stronger... With a Kh of 17 °dGH from tap in some areas, it will take years to get the pH under 7 due to KH drop alone.

Doubt anyone's measured it in a planted tank. In wetlands, they have. They doped a meter cubed wetland soil and plant chamber with N stable isotopes in Reddy's lab at UF in Gainesville. I wanted to track basically "who got what" in terms of bacteria oxidizers, submersed macrophytes and algae(my concern was more with periphyton at the time) with regards to NH3/NH4. They have a periphyton study group in southern FL. I might go back and see if anyone' done it yet. We cannot add stable isotopes in the field obviously........they use to many years ago(eye roll). I'd wished I'd done that rather than taxonomy of algae in a Florida spring.
 

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They are equal in vegetative growth, but our plants are not germinating, eg, from seeds. Algal spores do germinate and often require a trigger or host of triggers mostly.

Hello Tom,
thanks for answering. Given the diversity of things grouped under algae, I think we are only making general observations/theories here. So for example BGA might act totally unlike other algae ( because they are unlike algae and because some sp. have the ability to fix N2). GDA is also a nice thing, although NH4/NH3 and other factors may be the reason why it grows the first time. However still a worthy discussion even if one algae type falls under this behavior.

So when they are "adult" they are able to use NH4 just like plants. CO2 lowered pH, KH lowering and in general lowered pH will give no advantage to plants over algae on the topic of NH4/NH3 when mature algae cells (visible or not) are in the water already.

Did I understand you correctly that NH3 ( but not NH4) is one of the triggers that induce algae spores germination ?



Doubt anyone's measured it in a planted tank. In wetlands, they have. They doped a meter cubed wetland soil and plant chamber with N stable isotopes in Reddy's lab at UF in Gainesville. I wanted to track basically "who got what" in terms of bacteria oxidizers, submersed macrophytes and algae(my concern was more with periphyton at the time) with regards to NH3/NH4. They have a periphyton study group in southern.....

Interesting stuff. I really wonder how much NH3 is actually lost from high pH aquariums like africancichlid tanks through volatilization... Could one not do the stable isotopes test in a lab on a smaller scale first ? Grow some biofilm some plants maybe a anoxic area and feed a labeled isotope compounds ?

However, Green water (Phytoplankton) and NH3 do seem correlated, new planted tanks ....If they use ADA AS, which lowers KH, via peat and clay binding sites, you do not get green water.
Wish somebody told this to my 2 week old tank with fresh AS which had a marvelous green water bloom even with half the lights running now, EI dosing and yellow drop-checker levels of CO2. The only time it happened to me in 20 years of fish keeping... (well except when I had a pond but that was the seasonal spring bloom)