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What exactly causes BBA? Part 2 - Bacterial imbalance

Good job Andy. I can tell you I recently redid a tank and increased the light intensity which caused the anubias to melt at an alarming rate. Within a week almost all the leaves on four rhizomes each at least 6 inches long melted. The only surviving leaves were new. I since moved it all and I have begun regrowing it in another tank. I might note that in that time I saw no algae on the leaves. fwiw.
 
BruceF, sorry to hear that. As the plants were new, this could be due to them having been grown emersed (out of the water) and the change in being kept under water. That is certainly the case with Crypts.

Also, you may not yet have been infected by BBA. My planted tank didn't have BBA (it had everything else) until I received a plant that had been grown on (for a while) in a store. I didn't realise, put the plant, still in the pot, into my aquarium and wondered what it could be growing on the plant. Never been rid of some BBA ever since.

Hopefully if the rhizomes have survived, they will make a full recovery.

Thanks for the support. Andy
 
Oh no the plants were not new. I had grown all that out over the years from a single cutting, I just moved them from one tank to another and made a mistake with the light. My point was simply about the plants reaction to the new light. I've found the easiest way to clean up an anubias is to take it out of the tank and spray it with h202 and clean it with a soft toothbrush.
 

That's really interesting!

The alternative proposed here is that it is the bright light, the plant photosynthesising using HCO3- as its carbon source, an accumulation of OH- ions accumulating on the leaf which is attracting the Ca+ ions to accumulate on the surface (perhaps re-combining and depositing as CaCO3).

Great to see this effect on anubias.

Much appreciated.


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Oh no the plants were not new. I had grown all that out over the years from a single cutting, I just moved them from one tank to another and made a mistake with the light. My point was simply about the plants reaction to the new light. I've found the easiest way to clean up an anubias is to take it out of the tank and spray it with h202 and clean it with a soft toothbrush.

BruceF,

Apologies.

It just seemed to be a stronger reaction to light than I was thinking. Zozo's thread seemed more in line with what I was expecting.

I've chemically burned anubias and caused then to melt by dripping on neat Easycarbo and leaving it on for too long. Might it have been too much H2O2 that caused the melt?

What is working for me at the moment is lifting the anubias tied to stones out of the aquarium when I do a water change and putting them in a one litre box with 3ml of Easycarbo for about 15 minutes. However, H2O2 sounds really good too.

Andy


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That's really interesting!

The alternative proposed here is that it is the bright light, the plant photosynthesising using HCO3- as its carbon source, an accumulation of OH- ions accumulating on the leaf which is attracting the Ca+ ions to accumulate on the surface (perhaps re-combining and depositing as CaCO3).

Great to see this effect on anubias.

Much appreciated.


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So who needs a PAR meter?? :p We all should plant a Potamogeton.. :woot: :lol: Sorry...... :oops:
 
The Wikipedia entry for Nitrosomonas (autotrophic bacteria) states that the optimum pH range is between a pH of 6.0 and 9.0. In this experiment, the pH on the Potamogeton leaves reached a pH of almost 11.0. Could such an increase lead to the autotrophic bacteria becoming dormant / stop nitrifying / being overrun by the heterotrophic bacteria? The autotrophic bacteria are a million times more efficient at producing nitrites and nitrates than the heterotrophic bacteria. On the microscopic scale, does this production of a high concentration of nitrites / nitrates provide a defence mechanism, allowing the autotrophic bacteria to defend a surface and stop themselves from being overrun by the heterotrophic bacteria? If the light intensity increased and hence the pH on certain types of leaves increased and pushed the autotrophic bacteria beyond their upper limit, could they be overrun? Even if the pH exceeded the upper limit for both types of bacteria, the heterotrophic bacteria are more able to re-colonise as their populations can increase in size much more quickly. Once they have colonised the surface, are they then better able to support the BBA?

If this is the case, than more flow should help to even out the pH issue and thus less BBA would grow... The ever recommended 10x flow isn't a bad idea in that case.
 
Biofilms are pretty complicated things. As a biofilm builds up it can create its own anaerobic conditions within the layers. Besides bacteria there can be fungi and yeasts and I don’t know what else. It is very complicated stuff and after a while all I can say is aufwuchs.
 
BruceF, I think you're spot on, biofilms do appear to be really complicated.

I realise that I've ignored huge amounts of biology and chemistry in this proposal, but in my mind it seems to fit quite well as a framework, if you start to consider the impact the bacteria may be having and how they relate to the anecdotal evidence.

I wondered whether the maturity / thickness of biofilms has a role to play in algae growth too. Biofilms are secreted by bacteria (and other organisms), therefore the bigger the population on a surface, the more biofilm there may be. Do algae spores first attach to sticky biofilm before they put down roots? New leaves wouldn't have had time for biofilm to build up. Old leaves have. Is this part of the reason why older leaves are more effected? Does a fast growing leaf stretch the biofilm? Does the depth not reach a critical depth to let algae take off? Regarding the OH- ions, does the biofilm create a non or semi-conducting surface, allowing charge to build up or flow to the edges, but not completely disperse?

Not at all sure. As you say, very complicated when you start looking at them.
 
Not that I understand it but…………….

https://gupea.ub.gu.se/bitstream/2077/28022/1/gupea_2077_28022_1.pdf



Microcolony growth

One of the inherent properties of nitrifying bacteria in biofilms is their ability to

form microcolonies of varying size, shape and density (eg Schramm et al., 1996,

Schramm et al., 1999, Gieseke et al., 2003, Okabe et al., 2004, Hallin et al., 2005,

Papers I-IV, Fig. 6). These microcolonies are often structurally stable and difficult

to disintegrate without killing the bacteria (Larsen et al., 2008, Frank Persson,

persson-al communication) and it was recently shown that production of

extracellular DNA (eDNA) provides structural strength to the microcolonies which

contained high amounts of these molecules (Dominiak et al., 2011). Okabe et al.,

(2004) measured how nitrifier microcolony average size varied with depth and

organic carbon availability in the medium. They observed that AOB microcolony

size was rather constant throughout the biofilm when organic carbon was not

added. In contrast, size distribution was significantly stratified in the biofilm

39

residing in a reactor with a C/N ratio of 1, probably an effect of heterotrophic

bacteria outcompeting autotrophic nitrifiers in the surface layers of the biofilm,

where AOB microcolony size was the smallest. Gieseke et al., (2003) also observed

hetereogenous size distribution of AOB microcolonies and reported that

Nitrosococcus mobilis microcolonies were smaller in less densely populated biofilm

regions, whereas larger ones were often found together with AOB from the

Nitrosomonas europaea/eutropha lineage (cluster 7). In addition, Okabe et al., (2004)

observed that microcolonies of two different groups of AOB, belonging to

Nitrosomonas and Nitrosospira respectively, differed in their areal cell density and it

was speculated that the looser colonies of Nitrosospira would facilitate oxygen and

ammonium diffusion which could partly compensate for a lower growth rate. Such

loose microcolony structures have also been observed in Nitrosococcus mobilis

(Gieseke et al., 2003) and Nitrospira (Daims et al., 2001a). Microcolony

disintegration in Nitrospira has been reported as an effect of nitrate accumulation in

the system (Spieck et al., 2006). Spieck and colleagues (2006) hypothesized that

switching from microcolony to planctonic growth would be a straightforward way

of escaping detrimental changes in environmental conditions. Furthermore, it was

shown for the AOB N. europaea that NO gas functions as a signal for switching

between planctonic and biofilm growth (Schmidt et al., 2004a). Thus, several

observations indicate that nitrifier microcolony size distribution and density reflects

the ecophysiology of the organisms and the conditions prevailing in their

environment. Further discussion on this topic is found in the “Conclusions and
 
They observed that AOB microcolony
size was rather constant throughout the biofilm when organic carbon was not
added. In contrast, size distribution was significantly stratified in the biofilm
residing in a reactor with a C/N ratio of 1, probably an effect of heterotrophic bacteria outcompeting autotrophic nitrifiers in the surface layers of the biofilm, where AOB microcolony size was the smallest.

BruceF, thank you very much. The few sentences above really leapt out at me. Does this confirm that with a rising Organic Carbon / Nitrogen (C/N) ratio, the autotrophic bacteria are being out competed by the heterotrophic bacteria?

A figure of C/N > 1 is also mentioned in the following paper. This paper talks about how best to utilise nitrogen compounds in an intensive shrimp farming business, using autotrophic bacteria, heterotrophic bacteria or algae. They found that autotrophic bacteria functions best when C/N ratio < 1. Once the C/N ratio exceeds this, the heterotrophic bacteria begin to dominate.

http://www.sciencedirect.com/science/article/pii/S004484860600216X


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BruceF,

Just a few more things I'd like to highlight from your last post:

These microcolonies are often structurally stable and difficult to disintegrate without killing the bacteria (Larsen et al., 2008, Frank Persson,

Clean up crew (e.g. Otocinclus) grazing on the biofilm may break up the biofilm.

Nitrosomonas and Nitrosospira respectively, differed in their areal cell density and it was speculated that the looser colonies of Nitrosospira would facilitate oxygen and ammonium diffusion which could partly compensate for a lower growth rate.

Nitrosomonas (ammonia to nitrite) has the supply of the ammonium and oxygen it requires facilitated by Nitrospira (nitrite to nitrate). Interesting that they grow close together and help each other out.
 
Furthermore, it was shown for the AOB N. europaea that NO gas functions as a signal for switching between planctonic and biofilm growth (Schmidt et al., 2004a). Thus, several
observations indicate that nitrifier microcolony size distribution and density reflects the ecophysiology of the organisms and the conditions prevailing in their environment

If heterotrophic bacteria function anaerobically, they can convert nitrites / nitrates to NO and then Nitrogen, completing the nitrogen cycle.

NO may signal to the AOB that a large population of Heterotrophic bacteria exists that has insufficient oxygen to function aerobically. Their response is to build up biofilm to protect themselves.
 
{ASIDE}
The story of the mysterious red alga that I wrote about a couple of weeks ago (see “More than just an insignificant dot?”) has taken another intriguing turn. Having decided that the alga was probably Audouinella pygmaea, I was shown a paper from 2011 by Orlando Necchi and Marianna Oliveira in which they consider the affinities of Audouinella species and came to the conclusion that Audouinella pygmaea only really exists in the imaginations of people who write identification guides. I’ve written before about the complicated life history of red algae (see “The schizophrenic life of red algae …”) and commented that it can be hard to differentiate between simple red algae such as Audouinella and stages in the life history of more complicated red algae.
https://microscopesandmonsters.wordpress.com/tag/audouinella/
 
Thank you Andy for creating this thread, I have read it with extreme attention, and your theory fits perfectly my own experience. My tank suffers of BBA, pretty much constantly. It is the only algae that once In a while gives me real trouble. It gets stronger when I mess with substrate too much, and appears mostly on old Anubia leaves or on melting/old Valisnerias leaves. Valisnerias leaves that get BBA do have your mentioned biofilm!!

Here are some questions for you:

1. Considering that during the photoperiod (7-8 hours) my PH is always under 6.5 (6.2 exactly) due to Co2 injection, does that mean that autotrophic bacteria are likely to be dormant during that time? If so, how to solve this problem with Co2 injection?

2. I am wondering if liquid ammonia reducers can help to solve BBA issues. I have a bottle of that stuff, and added some of it to my tank after the last water change, yesterday, after reading this thread... I will let you know if it sorts any positive effect.

3. I am wondering what are the effects of adding bacterial additives.... Which bacteria are added by using generic bacteria additives? Can they help increasing the autotrophic population in some way? Or can that be detrimental because heterotrophic could accumulate even more? Is there ad additive that adds just autotrophic bacteria?

I am trying to find a practical way to apply your theory when BBA is present in the tank. I am eager to know your thoughts on all this. Thank you!
 
Maybe I am a little off track here but since we are talking about what I assume is a form of red algae


I don’t know how one copies from this link but see if you can get to page 448 and read the summary.

This is from the summary and relates to freshwater red algae.

“In general all morphological forms can be found in low PO4 concentrations ….” That along with neutral to acid ph and lots of light.

https://books.google.com/books?id=F...q=periphyton and fresh water red alga&f=false
 
Fablau, I'm really pleased to hear that you think that this theory has a good fit with your experience with BBA.

Like you, I'm struggling with BBA. I suspect that once you have it, the best we can hope to do is manage it.

There are many more people on this forum who are far more experienced and better able to advise you.

Unlike most, I've probably spent more time reading around this hobby rather than actually doing. This theory seemed to fit well with others experiences and recognised controls (backed up by scientific data).

The better you understand a problem, the more you can do to control it.

Based on this theory, I'll give you my thoughts. They're mostly controls others have found to work. However, I'll propose other reasons why they may work.

1. According to the Biocon Labs website autotrophic bacteria function less well at around a pH of 6.5 and stop functioning at about 6.0.

Having said that I have read elsewhere that there are a variety of species of Autotrophic bacteria, some of which may be able to cope with pH levels outside this range.

Therefore, you may see an increase in ammonia at your highest concentration of CO2, lowest pH, if the autotrophic bacteria are switching off.

Practically, limestone in an aquascape (e.g. ADA Seiryu or Ryouh) will lead to an increase in initial pH. If your aquascape would allow it, you could perhaps add some additional limestone rock to help buffer the water, perhaps preventing the pH dropping as low.

2. Ammonia is the main compound required by the nitrifying bacteria, as well as being a potential compound required by the BBA.

Managing the concentration of ammonia, rather than eliminating it would seem to be correct to me.

Ammonia is produced through fish waste and heterotrophic bacteria breaking down proteins and amino acids in organic carbons.

Practically, removing waste and a water change would help to reduce the source and concentration of ammonia. This will help to starve the heterotrophic bacteria of organic carbon.

Consider cleaning your filter to remove organics, to remove the heterotrophic bacteria's food source and improve the conditions for the autotrophic bacteria. The Autotrophic bacteria will be better able to compete, converting ammonia to nitrates.

Adding a liquid ammonia remover may help, but it may be a short term fix. It may not remove the source of ammonia (too many organics) and if used to excess it may limit the ammonia available to the nitrifying bacteria. Perhaps use with caution.

3. ADA produce Bacter 100 to help create the correct bacterial populations in the substrate.

The Biocon website suggests that you should take care in terms of the bacteria products that you can add http://www.bioconlabs.com/nitribactfacts.html

Once bacteria is in your aquarium (which you'll struggle to avoid) the population size will vary significantly with the environmental conditions. The population of the heterotrophic bacteria are able to respond much more quickly than the autotrophic bacteria to changes in the environment.

Therefore, minimising the organic carbon waste in your aquarium to constrain the population of heterotrophic bacteria enables the autotrophic bacteria to be better able to compete for surface area and oxygen.
 
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