# Vacuuming alters chemistry?



## Dolan (17 Sep 2018)

I have a high tech planted tank (albeit crap substrate)

I have noticed lately my Monte Carlo carpet does not pearl anymore, and a lot of BBA started cropping up everywhere.

I did a vacuum of all the detritus, and now suddenly all my plants seem to be doing well and pearl again.

Could the act of vacuuming alter some chemistry in the tank, or alter the heterotrophic/autotrophic bacteria?

I was told that you don't need to vacuum in a planted tank because it acts as plant food for my carpet?

Could the substrate be a factor of why I need to vacuum? I am using sharp-ish white gravel

So now I am doubly confused.


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## rebel (17 Sep 2018)

Vacuuming will help by removing the crud on the leaves which can block intake of light and nutrients. I would vaccuum judiciously.


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## azawaza (17 Sep 2018)

In my nano low tech 40 L tank, I use a turkey baster as a siphon to 'vacuum' my sand. Mostly, my targets are detritus and large unsightly fish waste or uneaten food. This would allow me more control over what I would and could remove from the sand substrate.


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## Dolan (17 Sep 2018)

azawaza said:


> I use a turkey baster as a siphon to 'vacuum' my sand.



Doesn't that just move the ditritus around? And not solve the problem?


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## AverageWhiteBloke (17 Sep 2018)

Have a look at the Dennerle Nano gravel syphon. Great little bit of kit for syphoning mulm and gubbins from the substrate and getting into tight spots. Could be that the plants are pearling again because you've removed a lot of waste from the substrate. I believe the process is called BOD (biological oxygen demand) Essentially the more waste the bacteria need to break down the more they demand oxygen to do the job, the bacteria are only limited by the amount of oxygen available. Pearling only takes place when the water column is super saturated with oxygen so would make sense that if the substrate is cleaner it requires less oxygen in the overall system then the water will saturate faster. Same applies to filter canisters which is why keeping them clean has benefits to the o2 consumption.

Could be wrong though but makes sense to me. I'm sure someone more informed will come along and say it isn't


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## Aquahorti (18 Sep 2018)

It is most likely due to the plants struggling that they are not pearling. I don't have any articles or measurements on oxygen levels in an aquarium over a 24 hour periode, but I have a couple of links to websites that have some useful numbers https://www.algone.com/oxygen-in-the-aquarium, https://www.water-research.net/index.php/dissovled-oxygen-in-water. I have not confirmed the numbers they have, but they seem reasonable to me, take them for what they are.
I see pearling from plants in my high tech tanks within a few minutes after the lights are being switch on in the morning, and I doubt that the DO levels are increasing that fast in the aquarium after 14 hours of lights off, that the pearling only occurs if the water is saturated (again I have no data to support this, but I will look for articles on the subject today).

The following article https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5349586/ describes experiments on release of oxygen bubbles from aquatic plants, some of them also being used in aquariums. As they describe in the article the acoustic noice from plants releasing oxygen bubbles constitutes problems in other aquatic studies using acoustic methods. 

In short, your plants are most likely not pearling due to them not having optimal conditions, and the organics between the plants and in the substrate is a contributing factor.


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## BubblingUnder (18 Sep 2018)

Dolan said:


> Doesn't that just move the ditritus around? And not solve the problem?



If you keep debris in suspension it doesn't build up so much, the current will move debris to the filter sponge.


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## AverageWhiteBloke (18 Sep 2018)

I guess debris is debris whether its sitting on the substrate, on the sponge or in the canister. It still adds to the biological/organic load, encourages algae and is an oxygen thief.


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## tiger15 (19 Sep 2018)

Aquahorti said:


> I see pearling from plants in my high tech tanks within a few minutes after the lights are being switch on in the morning, and I doubt that the DO levels are increasing that fast in the aquarium after 14 hours of lights off, that the pearling only occurs if the water is saturated (again I have no data to support this, but I will look for articles on the subject today).
> 
> The following article https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5349586/ describes experiments on release of oxygen bubbles from aquatic plants, some of them also being used in aquariums.


What type of plant do you see pearling within minutes light on.  Is it pearling or streaming, which is two different thing?

I am skeptical of the accuracy of the article cited.  It mentioned "stomata" that are known to be non-existent, poorly developed or degenerated in aquatic plants.   

"In photosynthesis of submerse water plants Oxygen emission occurs in form of bubbles which are released from the stomata or small openings caused by injuries."

What recorded in the experiment is streaming, not pearling, which can occur under non-saturated conditions.  Aquatic plant cells are leaky, and pearling can occur only under saturated conditions.


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## Aquahorti (19 Sep 2018)

tiger15 said:


> What type of plant do you see pearling within minutes light on.  Is it pearling or streaming, which is two different thing?
> 
> I am skeptical of the accuracy of the article cited.  It mentioned "stomata" that are known to be non-existent, poorly developed or degenerated in aquatic plants.
> 
> ...



I have seen it from Rotala, HC, Anubias, and Crypts, but as you most likely know many of the plants we use in aquariums are plants that can live above as well as under water, the same is the case for the plant that the poster is referring to.

I'm interested in the difference between pearling and streaming, I have always been under the impression that the term pearling is used for both when you have gas bubbles forming on the plants and when you see a fine stream of bubbles being emitted from the plants.

References/links to your claim that pearling can only occur under saturated conditions?

One of the plants (_Elodea canadensis_) used in the experiment does lack stomata http://www.vcbio.science.ru.nl/en/virtuallessons/leaf/submerged/, but how that invalidates the experiment eludes me, please enlighten me. 

Quote from the article: 

'Our many years of work with aquatic organisms as well as through the use of video recordings showed that the typical sound pulses during photosynthesis are not caused by the passage of the bubbles through the water surface, but upon emergence from the stomata. The same effects occur when air bubbles emerge from damaged plant tissue. This provides the opportunity to establish the exact time of bubble emission.'

/end Quote.


Quote:

'First, acoustic recordings were made in the herbaceous zone of stagnant or slow-flowing water on sunny days. Then, the exiting and rising behaviour of oxygen bubbles were studied on _Elodea canadensis_ in aquariums. For comparison some other hydrophytes (_Cryptocorine, Vallisneria, Myriophyllum_) were also tested.'

/end Quote.


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## tiger15 (20 Sep 2018)

Most aquatic plants in aquarium are swamp plants. I think all aquatic plants lack stomata regardless of whether it is fully submerged or semi emerged.  Stomata regulate moisture loss and gas exchange that is critical in terrestrial plants but not  aquatic.

Pearling can lead to some streaming, but streaming can occur  without pearling.


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## Aquahorti (20 Sep 2018)

tiger15 said:


> Most aquatic plants in aquarium are swamp plants. I think all aquatic plants lack stomata regardless of whether it is fully submerged or semi emerged.  Stomata regulate moisture loss and gas exchange that is critical in terrestrial plants but not  aquatic.
> 
> Pearling can lead to some streaming, but streaming can occur  without pearling.



Let me start with asking you again for links that will back your previous claims, as you have yet to provide any.

I assume you mean wetland not swamp?

It is irrelevant what we think if we can't somehow back it up, at least when we venture into the domain of science.  You fail to specify what you mean when you talk about 'all aquatic plants' but let us just for a second go with the definition given on page 13 and 14 in the following book https://books.google.dk/books?hl=da&lr=&id=3AgSBQAAQBAJ&oi=fnd&pg=PA3&dq=definition+of+aquatic+plants&ots=KE80UPtuGd&sig=p4aZeWbizD-JhqAWJ2gdp2qTm4Q&redir_esc=y#v=onepage&q=definition of aquatic plants&f=false and go from there. As you can see they find it hard to come up with a good definition as the lines are blurred but the plants we use in aquariums will for the most part fit the definition, but again you need to define what you mean when you talk about 'all aquatic plants' which you then can define as 'plants that lives under water and lack stomata regardless of whether it is fully submerged or semi emerged' but that leads to circular argumentation in this case...
I suggest you read the following article on gas exchange of some submerged plants https://nph.onlinelibrary.wiley.com/doi/full/10.1111/j.1469-8137.2007.02318.x (look at table 1 for quick reference) and just in case you feel inclined to question _Sparganium emersum_ (S) look at page 2024 in this: https://pdfs.semanticscholar.org/3590/93a3bc68b799568a337816deda79a393dd76.pdf, as they do have stomata.

The last part of your first line:

Quote:

'Stomata regulate moisture loss and gas exchange that is critical in terrestrial plants but not aquatic.'

/end quote.

Links please? I agree on most of it, but it hinges on what is meant by aquatic.

That last line is just meaningless, unless you define what pearling and streaming is. Replace Pearling with Heat and Streaming with Sublimation and most people will struggle as heat and sublimation are terms they do not have a firm grasp on.

You have also yet to explain how the lack of stomata on one of the plants in your mind makes the article questionable, please elaborate.

But again plants having stomata or not, have very little to do with the posters question with regards to why he didn't see any pearling, as the article https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5349586/ describes the release of oxygen bubbles from plants with stomata and as well as from plants without stomata.


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## tiger15 (20 Sep 2018)

Tom Barr has cited many times that many aquatic plants have no stomata, and even if they do, they are non-functional.

https://barrreport.com/threads/does...t-leaves-make-any-difference.4818/#post-31845


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## Aquahorti (20 Sep 2018)

tiger15 said:


> Tom Barr has cited many times that many aquatic plants have no stomata, and even if they do, they are non-functional.
> 
> https://barrreport.com/threads/does...t-leaves-make-any-difference.4818/#post-31845


That link contains nothing but hearsay 

Tom Barr have never given any links to actual research supporting his claims. I'm sorry but I have yet to find Tom Barr actually produce any links or references to his claims regarding EI, that is peer reviewed, nor to many of the other claims he have made that doesn't really agrees with established scientific research in the different areas. I do not do argument where evidence is based on appeal to authority https://en.wikipedia.org/wiki/Argument_from_authority and I do under any circumstances not consider Tom Barr an authority, so try again. 
You do not seem to have read through the links and articles I provided because if you had you would not insist on using terminology that is either not well defined or circular.

To be honest you are waisting my time here, as you are either unwilling to answer the questions I asked you or unable to do it, and either way this it not really helping the OP. As I have mentioned in a previous discussion we had, you are welcome to send me a PM if you still need things explained further.

Kind Regards,


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## tiger15 (20 Sep 2018)

Yes, many Tom Barr claims are empirical.  More often than not, they work in practice despite lacking peer review nor rigorous scientific evidence.  But so are other methods including Walstad that promotes a very different approach.

But I want to caution that peer reviewed scientific studies in ecology, though valid in outdoor environment, aren't necessarily applicable to aquarium environment.  Some findings fail terribly in aquarium, for example, high macro levels have proven to cause algae bloom in natural waters, but EI has proven it wrong.  

Unfortunately, there are no  scientific journals dedicated to aquarium plants which live in a very different environment.


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## tiger15 (23 Sep 2018)

To back up Tom Barr’s statement that aquatic plants have no stomata or no functional stomata, here is an article that describes the characteristic of Hydrophytes.

http://www.biologydiscussion.com/pl...aning-and-characteristics-plants-botany/75467

I am copying the summary bullets below.  Most hobbyists don’t know about it, but as a researcher who wrote journal article on hydrophytes ought to know this botanical fact. Although it may not affect the experimental findings, it casts doubt on the knowledge level of the researcher.

*Anatomical Features of Hydrophytes: *
1. Cuticle is completely absent in submerged parts of the plants.

2. Cuticle may be present as a thin film on surface of parts exposed to atmosphere.

3. Epidermal cells are with chloroplast useful for absorption and assimilation.

4. Stomata are totally absent in submerged hydrophytes.

5. Exchange of gases takes place through diffusion.

6. Non-functional stomata are seen in Potamageton.

7. Epistomatous leaves (stomata found only on upper surface) are present in hydrophytes with floating leaves Eg; Nelumbo.

8. Mechanical tissues like collenchyma and sclerenchyma are more or less absent

9. Xylem is poorly developed in Hydrophytes as the water absorption takes place all over surface of the plant body

10. Hydrophytes have aerenchyma in all parts of the plants. Aerenchyma proves provides buoyancy to the hydrophytes.


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