Algae Spores, CO2, Oxygen & Plant Growth

[NathanB]

I've recently been down a bit of a rabbit hole with plant biology, RuBisCO, and algae growth, and while reading a few very interesting threads like < Can Someone Explain Rubisco to me? > and < EI Calculators >, I've gathered peices of info that I'm having trouble fitting together, or at least I have some questions about them!

First up is this paragraph:

When plants are suffering an acute deficiency they actually leak more nutrients and organic products out into the water in what might be likened to diarrhea. Algal spores are sitting on top of the leaf and the spores can sense the release of these products, such as PO4 for example. So the logic in the algal spore monitors the PO4 output and can tell that if so much PO4 is leaking, then the plant is ill and it is a good time to attack.

So do not misinterpret this as "PO4 causes algae" but rather; "an increase in PO4 leakage from the plant tissue indicates a cell rupture and that means the prey is susceptible to attack"

My question is how does this differ in lets say an aquarium with no plants but constant algae growth? I feel like maybe im confusing myself by looking too much into it, but I love to learn about this and the science behind aquariums so I wanted to ask here. In this figurative aquarium with no plants, would it just be simplified by the fact that there is no competition for the algae? so it just grows based on nutrient/light/CO2 availability just as plants would if it was planted?

Because I also read this:

the mental prison people have been locked in for years thinking that nutrients cause algae

And it peaked my interest, is it just that I am underestimating the differences between a planted and non-planted environment/aquarium? or is it just that some species of algae "attack" unhealthy plants while other species of algae are happy just growing despite whether there are healthy/unhealthy plants in the aquarium or not?

Hopefully this makes sense..

Cheers.

 

[LMuhlen]

My thinking on this is that the algae evolved into having multiple triggers that optimize their chance of success, which may include very different scenarios. With the countless species of algae available, and I suppose even the same species may have different individuals with slightly different triggers, there should be enough things triggering algae in any situation in which the spores would benefit from hatching.

So while there probably are triggers like the one ceg mentioned, which indicate that there are plants susceptible to attack, there are probably other triggers that would identify an environment with enough light and nutrients and no competition, like a non-planted aquarium.

 

[dw1305]

Hi all,

or is it just that some species of algae "attack" unhealthy plants while other species of algae are happy just growing despite whether there are healthy/unhealthy plants in the aquarium or not?

With the countless species of algae available, and I suppose even the same species may have different individuals with slightly different triggers, there should be enough things triggering algae in any situation in which the spores would benefit from hatching.

What @LMuhlen says I think. For any situation with liquid water <"there is a an algae"> - <"General effects of eutrophication">.

...... Another example is the "green algae" <"Haematococcus pluvialis">, which is a bird bath specialist. Even persistent puddles will develop a <"species assemblage"> of "colonist" diatoms, green algae, protozoans etc. and these will then be replaced over time by other species......

A good example of a trigger would be in the resting stage of the Green Algae (Haematococcus pluvialis), where, if you have light, it is literally just <"add water">.

I've recently been down a bit of a rabbit hole with plant biology, RuBisCO, and algae growth

Green Algae are still "plants" <"Any advice on how to fix algae and poor growth?"> & <"Blog - Tiny but mighty: Algae hold the secret to turbo-charging photosynthesis in plants.">, some are adapted to <"eutrophic conditions"> and some to leaner rations, just like all other plants. If you don't have any higher plants then algae growth can be fairly spectacular <"A question, dissolved oxygen and a pond">.

We know that ammonia will trigger algal spore growth in some species, which isn't surprising, TAN is a scarce and patchy resource in natural situations <"https://royalsociety.org/~/media/policy/projects/evidence-synthesis/Ammonia/Ammonia-report.pdf">.

cheers Darrel

 

[ElleDee]

Unplanted tanks presumably have livestock or some sort, and their waste products provide algae with nutrients. Usually the limiting factor for algae in those tanks is light.

Algae as a whole is opportunistic, but not every kind thrives in every environment, and different species of algae compete against each other, not just against higher order plants.

 

[dw1305]

Hi all,

Usually the limiting factor for algae in those tanks is light.

Light is by far the easiest plant growth factor to remove. For those who <"like visual methods"> you can also see when you don't have any ..........

For the mineral nutrients I'd guess phosphate (PO4---) and iron (Fe), particularly as you can <"remove both at the same time">.

cheers Darrel

 

[NathanB]

I guess every single body of water no matter how big or small is going to be a totally different ecosystem with different water parameters and algae species, each competing against each other. So this statement that nutrients do NOT cause algae (which is new to me), is only the case with balanced well planted aquariums?

 

[ElleDee]

I guess every single body of water no matter how big or small is going to be a totally different ecosystem with different water parameters and algae species, each competing against each other. So this statement that nutrients do NOT cause algae (which is new to me), is only the case with balanced well planted aquariums?

Nutrients don't cause algae - algae comes from spores. They are one factor that can influence the growth of algae, but the relative importance of that influence depends on the overall environment. You can load up a tank with nutrients, but if there's no light, you won't get algae. On the flip side, there's enough chlorine and not many nutrients in my tap water that you can leave a glass of it in direct sun for weeks and it won't grow anything. It never comes down to a single factor, it depends on the system overall.

It's harder to get rid of algae in a planted tanks because plants and algae need the same things. That's how we end up splitting hairs about nutrients levels.

 

[dw1305]

Hi all,
What @ElleDee says.

So this statement that nutrients do NOT cause algae (which is new to me), is only the case with balanced well planted aquariums?

Unfortunately it is a "yes" and "no" answer <""Aquarium Science" has some new planted tank articles"> - <"Eutrophication drives regime shift via changes in stoichiometric homeostasis-based submerged macrophyte assemblages - npj Clean Water">.

The way I look at is that healthy, growing plants offer a multitude of advantages for tank management. It is a bit like triage in First Aid, <"plant growth is the thing you need to triage first">.

Personally I'm a <"lean doser">, but others will be <"much more successful"> than I am with heavier dosing regimes like EI.

The <"Duckweed Index"> was really designed for low tech plant keepers, but you can use it <"any situation">. I like lean dosing ("petrol fumes"), but others will use a <"lot more nutrients"> (<"triffid">*)

It uses a floating plant as your <"nutrient canary">, because floating plants have Diana Walstad's <"aerial advantage"> of <"access to atmospheric CO2"> (about <"424 ppm CO2"> today).

cheers Darrel