What are the root causes of Cyano?

[saltyfilmfolks]

Yes, it is but it is just as constantly taken up by corals and algae and in this way the concentration stays very low. Too low for much nitrification.

Would it not then contribute as well to cyano then?
Esp as a mat is formed?

 

[Lasse]

IMO - It’s a matter of probability - what’s catch the NH4 molecule first – a nitrosomas (nitrospira) bacteria – a algae or a zooxanthella (corals do not catch NH4 molecules – they are animals).

The nitrification cycle works well in saltwater – otherwise you should not to be able to have fish only aquariums without skimmers or not even skimmer free coral aquariums under construction.

I believe that the nitrification is rather effective over natural reefs – but for the NO3 molecule – it’s the same as for the NH4/NH3 molecule – it will not be long lived among all of these primary producers

For the lack of cyanobacteria mats in nitrogen (and phosphorus limited) natural systems – I do not have any good answer more than it’s a lot of grazers and more different competitors out there compared with the rather species poor aquariums that we have. In this case I have the same point of view as @saltyfilmfolks according to species diversity (miracle mud as an example). But I have to admit that you (saltyfilmfolks) found a weak chain in my explantion

The pathway for nitrite uptake among fishes is probably not so easy as you can say that it competes with the chloride uptake. It has been showed that the active uptake of chloride will continue, and the chloride cells will work harder in environment with nitrite and very low levels of chloride (i.e. the nitrite does not block the pathway for chloride uptake) – however in waters with chloride content over 60 ppm (half a table spoon of normal NaCl to 100 l -> 6 grams/100l) most freshwater species can stand high levels of nitrite because the chlorides will block the nitrite uptake. The normal explanation is that the chlorides block the uptake of nitrite not the opposite. It is only in the nearly total chloride free waters that nitrite can use this pathway in an active way In freshwater – there is believed that there is an ion pump (or similar mechanism) in the chloride cells that active exchange HCO3 with Cl

However - in a salt concentration over 0.7-0.9 percent thing will be complicated because this pathway will not be needed. The movement of chloride will instead go from the fish to the water but still (if the nitrite concentration is high enough – you will have brown blood disease – nitrite toxification). If anyone will have more information – just google “brown blood disease” and “osmoregulation in fish”

Sincerely Lasse

 

[Hans-Werner]

There is no lack of cyanobacteria in natural systems. Otherwise how could they be introduced to our tanks? And you even can find them on some images. Cyanobacterial mats don´t grow best on bare rocks but prefer sediments and sand.

Regarding the nitrification you have to keep two things in mind: In saltwater nitrite is virtually non-toxic because marine fish do not enrich chloride and nitrite but excrete chloride. So if not looking for nitrite, for example because of false-high nitrate results, it will pass unnoticed.
And nitrifiying bacteria need to get not only their nitrogen from the N-compounds as corals and algae do, the oxidation of NH4 and NO2 must fulfill their complete energy demand. Nitrifyers are chemoautotrophs.

 

[Brew12]

And nitrifiying bacteria need to get not only their nitrogen from the N-compounds as corals and algae do, the oxidation of NH4 and NO2 must fulfill their complete energy demand. Nitrifyers are chemoautotrophs.

Nitrifying bacteria are also fairly unique in the marine world in that they get their entire carbon demand from CO2 where most other bacteria in the ocean are carbon limited.

 

[Lasse]

@Brew12 I´ll think you mean CO3 - the carbonate ion

Cincerely Lasse

 

[Brew12]

@Brew12 I´ll think you mean CO3 - the carbonate ion

Cincerely Lasse

I'll need to look at it more, but I don't believe so.

http://www.sciencedirect.com/topics/agricultural-and-biological-sciences/nitrifying-bacteria

From the linked report.

"Obligate autotrophs obtain energy exclusively by the oxidation of inorganic substrates and use carbon dioxide as the only resource of carbon, such as the nitrifying bacteriaNitrobacter winogradskyi (oxidizing nitrite ion), and Nitrosomonas europaea and Nitrosococcus oceani (oxidizing ammonium ion)."

 

[saltyfilmfolks]

Cyanobacterial mats don´t grow best on bare rocks but prefer sediments and sand.

I have to say, I've experienced mars on rock , and have seen a lot growing in very thick mats on other members rocks quite a bit.
My assumption in several of these cases was different food sources in each case.
In my case , several at the rocks that consistently grew thick mats I removed from the system , placed in Fresh seawater w a powerhead , let soak for 24hrs and tested for Po4. No3 was not tested. Po4 was quite high on the rock.
Once returned to system , mats continued to form despite high flow.
Treatment for the system ultimately was even No3/Po4 reduction.
In fact , the last vestiges of bacterial matting occurred only on the rocks and not on the sand.

At the time , I took this as an indication of Po4 binding, in hindsight , I think it's quite a bit more along the lines of the micro climate thinking, where in the bacteria are helping to create and encourage localized conditions for growth once a location is colonized that has an abundance of one of the several key resources.
It one of the arguments against the balancing N/p theory, (not limitation that's different ), it was a completely localized event, and as I was using methods that are naturally No3 reduction weighted(wc and scrubbing) , I should have spurred a systemic bloom, save that I did ensure N availability (feeding fish healthfully)

 

[Hans-Werner]

I have to say, I've experienced mars on rock , and have seen a lot growing in very thick mats on other members rocks quite a bit.
My assumption in several of these cases was different food sources in each case.
In my case , several at the rocks that consistently grew thick mats I removed from the system , placed in Fresh seawater w a powerhead , let soak for 24hrs and tested for Po4. No3 was not tested. Po4 was quite high on the rock.

I was talking on the rocks in reefs. I think sediments and gravel are a more disturbed environment and cyanobacteria can settle there easier. The typical reef rock is covered by corals and algae and grazed by parrotfish. I think it is less likely that cyano mats will grow on reef rocks.

You can´t transfer much nitrate with a rock because nitrates are water soluble and stay in the water while much of the phosphate is bound to rock and gravel and can be transferred with a rock quite easily and efficiently. In fresh saltwater some of the phosphate will dissolve from the rock and appear when tested for phosphate.

 

[saltyfilmfolks]

I was talking on the rocks in reefs. I think sediments and gravel are a more disturbed environment and cyanobacteria can settle there easier. The typical reef rock is covered by corals and algae and grazed by parrotfish. I think it is less likely that cyano mats will grow on reef rocks.

You can´t transfer much nitrate with a rock because nitrates are water soluble and stay in the water while much of the phosphate is bound to rock and gravel and can be transferred with a rock quite easily and efficiently. In fresh saltwater some of the phosphate will dissolve from the rock and appear when tested for phosphate.

Got it. I was naturally referring to our tanks. There are a lot more mechanisms for cleaning in the wild. Animals , weather etc.

I do understand Po4 binding and its finding equilibrium with water and how our tests sample them.

What I would put forward is, there is enough Po4 bound to the rock , and enough organics on the rock (and water ) to directly feed the the colonists and allow Them to thrive and further allow them create mats promoting ability to create small localized environments they can thrive in.
So oft times it's not a systemic mechanism so much as a localized one.
We see this in spots of lower flow or constricted flow in tanks due to coral growth. In those localities the conditions were right for colonization and the organisms took advantage and by smothering the area nurtured the others.

In my personal observations above , I had wondered how and why p04 binding was not even, as the cyano was in only one spot on the rock, despite even flow and lighting. I my assumption is the other elements needed were there , Ie a pocket of die off , rot, organics , ammoina etc .
Although this is scientifically not binding , it is an accumulation of decomposing organics.

My solution to this was continued systemic treatment in nutrient level reduction and also allow the organisms use up the resources being provided locally. Eat themselves out of a job basically.
Moving forward in practice and maintenance, I keep good flow and blow detritus off the rocks regularly.

Its also one reason I don't reccomend chemi clean etc, as the conditions are and will still be ripe for colonization and we really can't say what else is being killed if that mat actually be helping to process those nutirients.

 

[Brew12]

So oft times it's not a systemic mechanism so much as a localized one.

Climate is systemic while weather is local.

I'm thinking bacteria only care about the weather, not the climate!

This highlights the problems with water tests. It only provides a snapshot of that specific parameter in the water at that specific time. This is why I typically have 0 to5ppm NO3 and 0.00-0.05 phosphates yet I feel I run a high nutrient system. Lots of food in, lots of algae out.

 

[saltyfilmfolks]

Climate is systemic while weather is local.

I'm thinking bacteria only care about the weather, not the climate!

This highlights the problems with water tests. It only provides a snapshot of that specific parameter in the water at that specific time. This is why I typically have 0 to5ppm NO3 and 0.00-0.05 phosphates yet I feel I run a high nutrient system. Lots of food in, lots of algae out.

I was referring to cyano growth.
And as illustrated, both are considerations.
So I kind of agree. You can have bad weather in cleavalnd (my low flow spot ) and get cyano.

Yet my Po4 hit .3 and I have no cyano in the tank despite global warming.

I don't test after I feed the fish. This appears to be one of the times when Po4 would "spike", I don't know of other times it would as Po4 in belive maintains equilibrium with the water for the most part. (Eventually someone will invent a constant Po4 test people will worry about all time too.


Yes. .3. No cyano.
(I put a mushroom and a lepto in cleaveland to catch the rain )

 

[Lasse]

I'll need to look at it more, but I don't believe so.

http://www.sciencedirect.com/topics/agricultural-and-biological-sciences/nitrifying-bacteria

From the linked report.

"Obligate autotrophs obtain energy exclusively by the oxidation of inorganic substrates and use carbon dioxide as the only resource of carbon, such as the nitrifying bacteriaNitrobacter winogradskyi (oxidizing nitrite ion), and Nitrosomonas europaea and Nitrosococcus oceani (oxidizing ammonium ion)."

This is not my experiences. I work in large system with a lot of CO2 in the systems. If the CO2 content get so high that the pH goes down below 6.8 - the nitrification stops. We have to ad HCO3 or CO3 to the system to have the pH around 7 and its work. There is also signs that if you - in freshwater planted tanks - rise the KH to around 4 with HCO3 and after that adjusting (with help of CO2) the pH to around 6.5 - the nitrification still occurs. But I have not tested this by myself. In Malawi, Tanganyika and salt waters tank with pH a bit over 8 (very low free CO2 levels) the nitrification process works well. This has been a debate among people dealing with these problems for decades and I very convinced that you need CO3 and HCO3 in the water in order to make the nitrification process smooth and good. I have never seen any time that low CO2 content in the water has inhibit the nitrification process but – I have seen 1000 of examples there low HCO3/CO3 but high CO2 level has stop it. But this is the source in the water I´m talking about – it has probably to be converted to CO2 inside the bacteria for the process

Sincerely Lasse

 

[Brew12]

I wish I had your guys experience and expertise. I just do my best trying to learn from reading.

If the CO2 content get so high that the pH goes down below 6.8 - the nitrification stops.

I have read a few studies that discuss how low pH causes nitrification to slow and/or stop but none of them address the cause of the stoping. I'm wondering if that is a different mechanism than the actual CO2 content. I wouldn't think even a relatively large population of nitrifying bacteria would consume much CO2. Certainly not enough to change pH.

 

[saltyfilmfolks]

I wish I had your guys experience and expertise. I just do my best trying to learn from reading.



I have read a few studies that discuss how low pH causes nitrification to slow and/or stop but none of them address the cause of the stoping. I'm wondering if that is a different mechanism than the actual CO2 content. I wouldn't think even a relatively large population of nitrifying bacteria would consume much CO2. Certainly not enough to change pH.

I belive they need o2 not co2.
That's what happens in nopox od. It sucks the o2 out of the tank.

High co2, low ph , low o2.

 

[Lasse]

@Hans-Werner

Things we agree about

No2 – nitrite is not toxic for gill breathing animals in saltwater with exception of ridicules high concentrations. In 2006 when I came from the dark side (freshwater) – I was nearly hunted down of a wolfpack of Swedish saltwater aquarists after a statement that saltwater was much easier than freshwater – you did not have to worry for toxic nitrite. It was not according to the saltwater textbook´s at that time .

The need to cycle of this reason (nitrite toxicity) is not so important. However – the concentration of created ammonia/ammoniac (NH4/NH3) can be so high that ammoniac (NH3) rise to toxic levels. There is two ways (natural) to minimise the NH4/NH3 content in water – nitrification and heavy aeration. The nitrification cycle is well-known – including the NO2 thing – heavy aeration (read oversized skimmers) is not as well-known process. At a pH around 8.0 – approximately 5% of the NH4/NH3 is in the NH3 form (25 degree C – more in higher temperatures) At a pH of 8.5 – approximately 15 % is in the toxic NH3 form. Its toxic – but its also a gas. A gas can be aerated out from the system and if NH3 is aerated out – the rest of the NH4/NH3 will be in the same percentage as before – this equilibrium will be instant when NH3 is aerated out. It takes time and the nitrification process is normally faster. To cycle a saltwater aquarium is therefore important but not from a NO2 toxicity point of view but for the case of toxic forms of the NH4/NH3 complex.

Things that we probably agree about

The importance and the occurrences of nitrification in a saltwater aquarium

Thing that we probably not agree about

The mechanism for NO2 uptake and the mechanism for the inhabitation of this uptake. IMO its not only a question of the direction of the chloride management in the gills. The inhibition take place in much lower chloride concentrations than those that change the direction of the chloride stream. The change is somewhere around 0.7-0.9 percent salt (7-9 psu) it corresponds to approximately 3800 – 4800 ppm chloride ions. It has been shown that a chloride content of approximately 60 ppm in the water inhibits the uptake of NO2 in rather high concentrations. A Chloride content of 60 ppm corresponds to a salt concentration of around 0.011 percent salt (0.1 psu). There are obvious other mechanisms involved in the inhabitation of NO2 uptake by the chloride cells than only the direction of the transport.

What we do not agree about (As I see it) – nitrification rate at natural reefs

The nitrification rate in a natural reef community – you claim it low – I claim it high

Let me sort it up from my horizont

Source of ammonia at a reef.

direct emissions of NH 4 / NH 3 from fish (through active/no active transport in the gills)

Decomposition of organic matter (bacteria breakdown - anaerobic/aerobic)

Transport of NH4/NH3 from deep anoxic water (upwelling)

Consumption and transforming processes

Consumers of NH4/NH3 – algae (benthic and planktonic), zooxanthella

Transformer of NH4/NH3 - nitrification bacteria and bacteria involved in the annamox process.

The annamox process is an important process in the nitrogen cycle but it is an anaerobic process and I will try too only handle the NH4/NH3 reaching the oxygen rich environment of a reef. For sure – there can be places in the reef there this process is the most important player but for the moment I only mention the process.

When

On a 24 hour schedule the contribution of NH3/NH4 to the reef will be constant (more or less) from the bacteria breakdown and the upwelling process. The Nh4/NH3 contribution from fish and other animals on the reef will probably be higher during the 12 hours of daytime – more in the move and eating.

In the same 24 hours period will the uptake of NH4/NH3 from photosynthesizing organism only happen during the daytime and mostly in periods of full day light. During nighttime and tropical storms will this part of the NH4/NH3 uptake be lost.

Hence – during no photoperiods – there will be plenty of NH4/NH3 for the nitrification process over the whole reef and during daytime – there will be nitrification in the deeper parts of the reef and places in dark or shadow. Nitrification is not light depended – uptake through photosynthesis is.

Demand of nitrification

Now – it’s the environment for nitrification at a reef good enough or not?

First – let us conclude that nitrification can take (and take place) in saltwater. It could be in a lower paste, but it works rather well.

What do the chemoautotrophs need? They need oxygen – a lot of oxygen on limit in the literature is 5 ppm for the second step (NO2->NO3), they need places to sit on, they need movement, so the biofilm will be thin, they are slow growers – therefor they need low organic carbon in the water (the fast-growing heterotrophs will outcompete them for place if there is a lot of organic carbon around) and they need a inorganic carbon source (and HCO3 and CO3 works as that) – and of cause – they need a constant flow of NH3/NH4.

How it looks like at a reef? Oxygen – check; place to sit on – huge contact areas between substrate – and water – check; water movement – check; low diluted organic carbon (DOC) – check; inorganic carbon source they can use – check and constant flow of NH4/NH3 – check.

Let me put it this way – I can’t construct a better nitrification filter than a living reef by myself

And I think it’s easy to investigate this in a normal reef. If I´m right, you should see a constant level of NH4/NH3 (probably zero) during all 24 hours of a day but a rising content of NO3 during the dark 12 hours of the day

Sorry for a huge post – but I´m that way – take it or leave it

Sincerely Lasse

 

[Lasse]

I belive they need o2 not co2.
That's what happens in nopox od. It sucks the o2 out of the tank.

High co2, low ph , low o2.

Its not a question of O2. I have (and still do) run nitrification filters that get 40 cubic meters of air/h (for 20 m3 water/h) Oxygen level at the outlet 100% saturation. As soon the pH drops below 6.6-6.8 nitrification rate goes down. To have it works all the time – we have a pH meter in the outlet – as soon is below 7 – we dose HCO3 in the inlet. These filters (around 5 m3) can handle 30 kg of fish pellets a day with NO2 levels at the outlet very low. The CO2 levels is also very low because of the heavy aeration

Sincerely Lasse

 

[Brew12]

I belive they need o2 not co2.
That's what happens in nopox od. It sucks the o2 out of the tank.

High co2, low ph , low o2.

I have to say that the more I look into this the more confused I am becoming. The article (and a few others I could link if you want) was definitely referring to CO2 since it was talking about carbon uptake. I think I need to do more studying on how other marine bacteria, like cyano, uptake carbon. Maybe it will make more sense.

 

[saltyfilmfolks]

Its not a question of O2. I have (and still do) run nitrification filters that get 40 cubic meters of air/h (for 20 m3 water/h) Oxygen level at the outlet 100% saturation. As soon the pH drops below 6.6-6.8 nitrification rate goes down. To have it works all the time – we have a pH meter in the outlet – as soon is below 7 – we dose HCO3 in the inlet. These filters (around 5 m3) can handle 30 kg of fish pellets a day with NO2 levels at the outlet very low. The CO2 levels is also very low because of the heavy aeration

Sincerely Lasse

So you are saying they don't need oxygen? And don't put out co2?

 

[Lasse]

So you are saying they don't need oxygen? And don't put out co2?

No No – Love, peace and misunderstanding they use a lot of oxygen and put out some as CO2 but mostly they use the O2 for the NO2 and NO3 molecule when they transform NH4 to NO2 and NO3 (in the last step). Thee O for every N atom! But in the building of bacteria cells - they need a lot of carbon. But they are autotrophs like plants and algae, they need inorganic carbon in order to build organic matter. This they take from the water and the main source (IMO) is HCO3 and CO3 – not CO2 in the water as many algae is capable to use

Sincerely Lasse

 

[Lasse]

Dubble post
Sincerely Lasse