What limits algae?

[Jim Miller]

After reading all about EI, CO2, lighting, etc, on this site including papers such as the Tropica one I still don't get one thing.

Why does a tank that grows plants well i.e. at the desired rate, not grow algae just as well at the same time? Aren't algae just plants albeit simple ones?

Jim

 

[Biollante]

'Cause

Hi,

Presumably higher plants evolved because it provided competitive advantages over those plants that did not.

Biollante

 

[Jim Miller]

No argument there. The question for me is what are those competitive advantages?

Thanks

Jim

 

[Tom Barr]

Are they competing at all?
Are they in the same/similar ecological niches?

Why is there more than 1 type of algae?
Why is there more than one type of aquatic plant?
Why are many aquatic systems dominated by very low species diversity(both natural and man made water ways)???

The fact of the matter is that folks do not know the answer to this.
I do not, but some hobbyists like to act and suggest that they do, when in fact, they have very little humility and understanding about the matter.
And I often have torn them new ones over it.

The only researchers I'm aware of that have a chance at getting at these questions are at UF in Gainseville.
Crisman is honing in on CO2 and the variation, good guy and some of the other folks there are retiring soon.

But there's some really hard things to try and test to answer some of these questions definitely, the same is very true for allelopathy.
Our systems are much more transient and easy to replicate, nature and old undisturbed locations that have trees and sediments that are 1000 years old??
Very tough. Plant Ecology is tough business. Competition is not easy to study and measure overall.
This same question has been asked many times. Going on 15+ years and counting.

Everyone has long thought in nutrocentric terms, but this has not been the case for 15 years and in natural systems was also disproven to have any correlation(see: http://fishweb.ifas.ufl.edu/Faculty Pubs/CanfieldPubs/macrophyte.pdf )
They Concluded that plants define the system, not nutrients. I concur and oddly agreed with them, they with me when I 1st discussed this, I was blown away, I thought there's be a heated debate, but nope, they had even more support from natural systems, myself, from aquariums.

Now how the plants are able to do this is not clear.
That has not been answered.

I think allocation of nutrients and Carbon from CO2 plays some role.
Algae might be able to "tell when someone else is there" in high enough density for it not to be a good time to germinate their spores and grow/bloom.

If this "someone" suddenly stops growing for a awhile, they can tell that also.
This is also true for algae-algae and perhaps plant-plant systems, not just algae vs plants.

Messing with CO2 supply funksup virtually every pathway in plant biochemistry.
Plants adapt to specific levels, and if those levels are changed often, too frequently, this leads to poor growth.

Nutrients?
To some degree also, but less so.

Most of the so called smoking guns have been tested and remain very inconclusive.
Aquarist have extremely bad control set ups, particularly the clowns and bozos who claim they know it all about algae.
I know if I focus on the plant needs, I will not get algae, but I do not know why really.

There's a difference, I do not seek the answers, I seek to understand the questions.

Regards,
Tom Barr

 

[Matt F.]

Are they competing at all?
Are they in the same/similar ecological niches?

Why is there more than 1 type of algae?
Why is there more than one type of aquatic plant?
Why are many aquatic systems dominated by very low species diversity(both natural and man made water ways)???

The fact of the matter is that folks do not know the answer to this.
I do not, but some hobbyists like to act and suggest that they do, when in fact, they have very little humility and understanding about the matter.
And I often have torn them new ones over it.

The only researchers I'm aware of that have a chance at getting at these questions are at UF in Gainseville.
Crisman is honing in on CO2 and the variation, good guy and some of the other folks there are retiring soon.

But there's some really hard things to try and test to answer some of these questions definitely, the same is very true for allelopathy.
Our systems are much more transient and easy to replicate, nature and old undisturbed locations that have trees and sediments that are 1000 years old??
Very tough. Plant Ecology is tough business. Competition is not easy to study and measure overall.
This same question has been asked many times. Going on 15+ years and counting.

Everyone has long thought in nutrocentric terms, but this has not been the case for 15 years and in natural systems was also disproven to have any correlation(see: http://fishweb.ifas.ufl.edu/Faculty Pubs/CanfieldPubs/macrophyte.pdf )
They Concluded that plants define the system, not nutrients. I concur and oddly agreed with them, they with me when I 1st discussed this, I was blown away, I thought there's be a heated debate, but nope, they had even more support from natural systems, myself, from aquariums.

Now how the plants are able to do this is not clear.
That has not been answered.

I think allocation of nutrients and Carbon from CO2 plays some role.
Algae might be able to "tell when someone else is there" in high enough density for it not to be a good time to germinate their spores and grow/bloom.

If this "someone" suddenly stops growing for a awhile, they can tell that also.
This is also true for algae-algae and perhaps plant-plant systems, not just algae vs plants.

Messing with CO2 supply funksup virtually every pathway in plant biochemistry.
Plants adapt to specific levels, and if those levels are changed often, too frequently, this leads to poor growth.

Nutrients?
To some degree also, but less so.

Most of the so called smoking guns have been tested and remain very inconclusive.
Aquarist have extremely bad control set ups, particularly the clowns and bozos who claim they know it all about algae.
I know if I focus on the plant needs, I will not get algae, but I do not know why really.

There's a difference, I do not seek the answers, I seek to understand the questions.

Regards,
Tom Barr

That's one hell of a good read.

 

[dutchy]

Isn't it all about chemical signaling? Not from the plants, but from the substances present or absent in the water? I don't think there's another way for algae to know conditions are favourable than through chemical signaling. We already know that NH4 is a good algae trigger. This can also work reversed. The chemical signal for algae is present at the moment that a substance, like NO3, CO2, O2 etc, falls below a threshold that makes the algae germinate. This makes algae fill a niche where it has a chance to complete its lifecycle. Once established, it even can grow in the range where plant growth is possible.
So let's assume that plant growth stops at 0,1 ppm of NO3, and a certain algae will receive a germination signal at 0,05 ppm of NO3. Being very close together, it will look like the cause is stagnant plant growth, while the real cause is the NO3 falling beyond the germination threshold. Now these germination signals could have various causes, like falling CO2 ppm's etc.
The other way around, algae can thrive far into the area where plants can grow. But the continous lack of chemical signaling (like restored and stable CO2 ppm's) will stop the algae from growing and eventually disappear.

This is all about ecological niches, not about competetion.

I also think that lack of light is a good limitation factor for algae.

regards,
dutchy

 

[Jim Miller]

So my take away is "we don't (yet) know". I'm OK with that, I just thought I had overlooked something in my study. I'm a retired engineer and noob aquateer but I enjoy learning.

I'll just strive to keep my aquazone limited by light-only through EI and enjoy the result.

Thanks

Jim

 

[ArnieArnie]

Take a look at your local pond. During spring plants are growing, when summer comes algae take over. (at least this is what I observe, not the same for every pond). There is a similar thing with bacteria known as "quorum sensing" (google it), I'm not saying it is exactly what algae do but it lets me think about it.

Greets

Arnoud

 

[barbarossa4122]

But, if we do not know that much about plants and algae how do we keep it out of our aquariums. I do not have any algae so far and I don't know how did I manage this without co2. Now, I have the co2 (4th day) and I sure am curious to see what will happen.

 

[Tom Barr]

But perhaps phytochrome plays a role.
Certainly seems to with many species of algae spores that germinate.

The real question is what causes algal spores to germinate and how each specific species respond to light and chemicals.
The other factor is really that subtle changes in nature can cause a large cascade down the road.
For us in our highly modified horticultural aquariums, these play less role.

So the spores sit and wait.

Even in well balanced natural systems, there is still some algae and some patches.
These might be a few feet apart and vary up and down the stream, around the pond/lake etc.

Regards,
Tom Barr

 

[Tom Barr]

But perhaps phytochrome plays a role.
Certainly seems to with many species of algae spores that germinate.

The real question is what causes algal spores to germinate and how each specific species respond to light and chemicals.
The other factor is really that subtle changes in nature can cause a large cascade down the road.
For us in our highly modified horticultural aquariums, these play less role.

So the spores sit and wait.

Even in well balanced natural systems, there is still some algae and some patches.
These might be a few feet apart and vary up and down the stream, around the pond/lake etc.

Regards,
Tom Barr

 

[Tom Barr]

So how mighty you test between competition and simply the algae being in a different ecological niche?
What would you test that would allow you to make such a conclusion?

Regards,
Tom Barr

 

[ArnieArnie]

Away to do this is go into genetics. Get algea in the different stages, collect RNA and see which genes are down regulated or up regulated that involve the metabolic pathways. This way you could get an understanding of the different enzymes at play. Fancy words aye
This stuff is for the human part still all new and in development. I would not know how to begin but I bet there are already institutes working on this.

 

[Biollante]

Why Is the Sky High?

Hi,

“Just because” sometimes is the answer, for the time being anyway.

Tom Barr’s post #4 is downright eloquent. :gw

I have tanks (and tubs and kiddies pools) outside and throughout the year I get algae of various sorts, each change seems to bring round(s) of algae.

Over the years I have learned not to get too excited about algae. Sure enough most go away in a week or three.

As Tom Barr says, focus on what is good for the plants.

The funny thing is from the days of my misspent youth on, I cannot recall fishing or swimming in any (natural) body of water that has no algae.

I am always amazed at folks claiming to set up a “biotope” or “natural” aquarium,crying, whining, in some cases being nearly suicidal over a little alga.

Personally, I like the “signaling” and I love “quorum sensing” as among the ultimate answers.

Biollante

 

[dutchy]

So how mighty you test between competition and simply the algae being in a different ecological niche?
What would you test that would allow you to make such a conclusion?

Regards,
Tom Barr

If CO2 drops, you get BBA. When CO2 is at a stable unlimited level, there's no BBA. When CO2 drops, it gets limiting, but there's still plant growth. Anyway you get BBA. I have repeated this test. So the signal for the algae to grow is falling CO2 ppm's, because there is plant growth as well as algae growth.

Plants can never outcompete algae because they can never deplete the water column so much that algae is unable to grow or germinate.

I see it as two ecological niches, image two circles that partly overlap each other, where the algae germinates in its own niche but is able to maintain themselves into the plant niche, but growing plants are not able to maintain themselves in the algae niche.
In the past I was able to grow great plants but I also grew great algae at the same time. If competition was the issue, this wasn't possible, because only one could exist at a given time.

 

[Biollante]

Sorry To Butt-In

Plants can never outcompete algae because they can never deplete the water column so much that algae is unable to grow or germinate.

I see it as two ecological niches, image two circles that partly overlap each other, where the algae germinates in its own niche but is able to maintain themselves into the plant niche, but growing plants are not able to maintain themselves in the algae niche.
In the past I was able to grow great plants but I also grew great algae at the same time. If competition was the issue, this wasn't possible, because only one could exist at a given time.

Hi Dutchy,


I know you were not addressing me, but I'll ask anyway.



Why can't more than one species exist in competition with each other?


Even though one may be more successful than the other both can exist, can't they?



Biollante

 

[dutchy]

if I was competing with you for food I would try to make sure you don't get any. That would give me more longevity. A plant can not outcompete algae for nutrition because algae can still survive in an area where the plant can not.

There is an area where both can thrive, I mentioned this in my overlapping circles. So where is the competition? The only thing I see is eating out of the same bowl.

 

[barbarossa4122]

So, the "trick' is to give the plants enough co2 and ferts.........to out compete the algae ? Can algae survive on little food/scraps ?

 

[dutchy]

Algae is never limited, so can live on "scraps" where plants are starving already.

So with some species of algae, the question is: "what's missing", not "what is there too much".

We are not outcompeting the algae, it's bringing the environment out of the algae's ecological niche.

If rising NH4 can trigger algae (chemical signal) to germinate it might as well be that other nutrients falling below a certain threshold can cause algae to germinate. Rising NH4 is not detrimental to plant growth, but still the algae germinates. No competition here.

(The posts are just my thoughts and observations, I don't claim them to be true ).
regards,
dutchy

 

[gillt]

"The only thing I see is eating out of the same bowl."

I agree that it would not seem to be a matter of competition because algae can survive in every environmental plants can, but plants cannot survive in every environment algae can. Plants it would seem can't out-compete algae because algae thrives in much lower nutrient and light conditions than plants, or so I thought.

But if they're eating out of the same bowl, what's stopping algae from eating everything since it has a higher rate of growth?

Possible and incomplete answer: Some algae seems to thrive at higher light levels than what plants respond to; by limiting light (photo-period/intensity?) you're limiting the growth of algae.

Another factor: what is it about increased CO2 that hinders algae growth? And why can non CO2 tanks still have very limited algae growth?