# Riddle me this



## Diana (Jan 14, 2010)

I like that Q:

Tank One has plants, low water level, fertilizer for the plants. Do the plants use all the fertilizer? 
If the plants are exposed to the air they are getting the CO2 from the air, and if they are under water by just an inch or less they are still getting high CO2. CO2 does reach equilibrium in that top inch of water pretty fast, so as fast as the plants use the CO2 it is replaced. So, in this tank you are not CO2 limited. 

Tank two just got filled with rain water, no nutrients, so nothing lives in it. It does not matter how much or how little CO2 is in that water, there is nothing else to support life. The limiting factor is no N, no P, no K, no traces... no nothing.


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## mistergreen (Dec 9, 2006)

That's a good point about CO2 being high in low water level in the emersed tank.

And you can starve algae but you'd stave the plants too


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## Diana (Jan 14, 2010)

Sounds like the tank with the plant balls has reached an almost algae-free equilibrium. The right balance of nutrients with light and CO2 so that the conditions are stable, the plants thriving. This is the goal of planted aquariums: Thriving plants keep the algae at a minimum. 
All too often there is not enough CO2 in the aquarium, or varying levels of CO2, and this is often when algae seems to take off.


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## TheFoleys (Jul 30, 2012)

Maybe that Ohio rain has enough hci in it to keep it barren without anything to neutralize. And would be devoid of any nutrients past the point that the atmospheric N gassed out when the temp rose. If you had a plant in there. The conditions would cause it to rot giving of some nutrients for some healthy algae!


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## HD Blazingwolf (May 12, 2011)

sunlight is naturally a disinfectant. it produces oxidizers much the same way a UV light does. its not so much related to co2. 

a planted bucket with 50% or more plant mass with decent nutrients will likely get no algae as well. i've had them. plants will define the system
BBA responds to fluctuating co2 first and the problem is exacerbated by high light.. and since the water isn't changing much, its not fluctuating

I AM surprised that the empty bucket has yet to grow anything though
very


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## mistergreen (Dec 9, 2006)

HD Blazingwolf said:


> sunlight is naturally a disinfectant. it produces oxidizers much the same way a UV light does. its not so much related to co2.
> 
> a planted bucket with 50% or more plant mass with decent nutrients will likely get no algae as well. i've had them. plants will define the system
> BBA responds to fluctuating co2 first and the problem is exacerbated by high light.. and since the water isn't changing much, its not fluctuating
> ...


How do you explain a pond choked up by algae? We've seen plenty of ponds like that. It gets plenty of sun.


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## plantbrain (Dec 15, 2003)

BBA seems to require flowing water and a CO2 optima of 5-10ppm.
Sheath & Wehr 2003.

Riddle solved


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## plantbrain (Dec 15, 2003)

mistergreen said:


> How do you explain a pond choked up by algae? We've seen plenty of ponds like that. It gets plenty of sun.


Does it have BBA?

Not likely.


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## plantbrain (Dec 15, 2003)

My turn: 

I walked down a stream about 3 weeks ago, Putah Creek near Davis, CA.
Creek is fairly clear water in most sections. I needed a certain species of weed propagules for an experiment. So bucket and boots in hand, down the stream I go.

Some sections were covered with long Spirogrya and diatoms so you could not see anything below, roughly 10-20cm deep from top of the water to the bottom.
right next to this, the plants were growing and clean without algae. Further down, some plants were matted with algae, further down, no algae on one section of the stream, but across on the other side, lots of algae of various species.

Down farther, a shallow section had Vaucheria algae, some bright green attractive Pithophora and some encrusting greens and diatoms on the rocks. 
Next to this in slightly deeper water was a good deal of the plant propagules I wanted.

I pulled them up and they were clean as a whistle. 

You could walk up and down this stream and find no less than 6 different species of (angiosperms) aquatic weeds. Some sections had been covered with hair algae, others were absent of any plant growth or algae, other sections were full of clean healthy growing aquatic weed beds.

Nutrients in the water column explains zero correlation here.
Light? Perhaps, but the far side is shaded, but the sunny side gets the same/similar light up and down the creek most of the day.

Possible causes:
Velocity of the flow/currents/seasonal timing of the observation(hardly any hair algae in the winter), sediment type(this is deposited based on water flow/currents), scouring, bends in the flow of the stream.

Still, there are many good examples in and within aquatic plant beds in natural system that lack algae and are also covered within the same system. Seasons play a large role in this.


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## mistergreen (Dec 9, 2006)

plantbrain said:


> Does it have BBA?
> 
> Not likely.


No, lots of hair algae. I'm not Sure about the disinfectant algae theory.

Cool about BBa requiring moving water. I see BBa all the time in streams. It totally makes sense.


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## mistergreen (Dec 9, 2006)

I would think different levels of nutrients in the sediment as the cause. Plants would use up the nutrients and die off so algae grow on them.



plantbrain said:


> My turn:
> 
> I walked down a stream about 3 weeks ago, Putah Creek near Davis, CA.
> Creek is fairly clear water in most sections. I needed a certain species of weed propagules for an experiment. So bucket and boots in hand, down the stream I go.
> ...


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## HD Blazingwolf (May 12, 2011)

it was just a theory as far as algae is concerned.
as far as the disinfectant part. the sun does disinfect things to a small extent.

UVC lamps work off a similar principle but are more powerfull for close range work

similar to how lightning creates ozone which is why lightning storms smell sooooo awesome!!!!!!

and how were those ponds maintained? what type of plants? we've also seen plenty of ponds that grow awesomely healthy happy plants. that statement unfortunately can lean both ways as tom pointed out via the stream subject

i recently while waiting for my father's pond dirt to stop leaching tannins and ammonia, filled a bucket with RAOK plants and some miracle grow ferts. green algae took horrible hold on everything for about 3 days and then water was crystal clear after that. bucket stayed in direct sun for 4 weeks while waiting and i added more miracle grow every week. algae never reapeared. swords, crypts, ludwigia repes, and frogbit that i constantly scooped out
oh and some blyxa

forgot to mention that the plants grew and made up at least 60% of the volume in the container


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## plantbrain (Dec 15, 2003)

mistergreen said:


> No, lots of hair algae. I'm not Sure about the disinfectant algae theory.
> 
> Cool about BBa requiring moving water. I see BBa all the time in streams. It totally makes sense.


Yes, "some" hair algae is a sign or good conditions, so is BBA.

Disinfectant algae theory?

You mean like not allowing any spores to get into the tank?
This might be true for BBA, hair algae and Cladophora. Maybe GDA, but not most of the others, very hard to do for most that add and try new plants often(like me).


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## plantbrain (Dec 15, 2003)

mistergreen said:


> I would think different levels of nutrients in the sediment as the cause. Plants would use up the nutrients and die off so algae grow on them.


This does not explain why the algae are where they are at.
Only the plants.

So that's only part of it and the part that grows plants, not why algae is in one place, but a few feet away, it is not.

I measured the current and sometimes they are the same between the plants and the algae beds.

But there is clear and distinct zonation with the plants and the filamentous algae. I'm not sure why, there is plenty of nutrients in the stream, it travels for many miles and gets all the agricultural run off from nice Class A soil, the water is loaded, almost a point source pollution source.

Mostly from April till maybe Dec/Jan it's pretty juicy. After rains flush the system and couple of times good.


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## HD Blazingwolf (May 12, 2011)

plantbrain said:


> Yes, "some" hair algae is a sign or good conditions, so is BBA.
> 
> Disinfectant algae theory?
> 
> ...



Hes remarking on my comment that the sun has disinfectant properties.
It was a theory as to why some plants or systems have no algae in full sun.
The sun does mildly inhibit grow of bacteria and fungi as well as creating peroxides in the air the help control vocs and airborne odors.
So i remarked that the sun may affect algae growth as well, kind of a stupid theory as algae is photosynthetic and is reliant on. Duh the sun


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## PlantedRich (Jul 21, 2010)

Life might be quite simple if we really understood the full workings of nature! I'm guessing there are lots of variables in that stream that we just know nothing about at this point in time. 
Any time I begin to think we know a lot about nature, I'm reminded of the medical field where we once held the theory of "laudable pus" in high esteem! It was fully understood that a wound had to have a good amount of pus before it would heal. 

We may be at about the same level with our understanding of algae!


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## plantbrain (Dec 15, 2003)

HD Blazingwolf said:


> Hes remarking on my comment that the sun has disinfectant properties.
> It was a theory as to why some plants or systems have no algae in full sun.
> The sun does mildly inhibit grow of bacteria and fungi as well as creating peroxides in the air the help control vocs and airborne odors.
> So i remarked that the sun may affect algae growth as well, kind of a stupid theory as algae is photosynthetic and is reliant on. Duh the sun


The algae are good at living in full sun.
No more disinfecting than say towards plants that live in full sun.

They use the same photosynthetic machinery and enzymes(very true for most of the higher multicellular and filamentous Green algae).

Which is why they are a PITA to the hobbyists.


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## plantbrain (Dec 15, 2003)

PlantedRich said:


> Life might be quite simple if we really understood the full workings of nature! I'm guessing there are lots of variables in that stream that we just know nothing about at this point in time.
> Any time I begin to think we know a lot about nature, I'm reminded of the medical field where we once held the theory of "laudable pus" in high esteem! It was fully understood that a wound had to have a good amount of pus before it would heal.
> 
> We may be at about the same level with our understanding of algae!


I find once I answer one little isolated thing or rule something out.....then the question becomes...........or several more pop up to take its place.

And I think that is really cool.

It's not so much what you know and can answer, it's what types of questions and directions you can go.
The path of life, in this case, the path of stream aquatic biology, or pond/shallow lake ecology(there's a good text book on this latter subject).

What types of relationships are present and what can/do we learn from this path? It can all start with a humble little glass box with aquatic weeds.

"From so simple a beginning" I think Darwin once stated sublimely.


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## mistergreen (Dec 9, 2006)

It's true that the sun does cause damage to organic matter including the photosynthic components. I read that the cell has an self repairing structure.


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