What are the root causes of Cyano?

[Sallstrom]

Yes, there are a lots of myths. High NO3 and lots of algae for example But thats probably too much off topic.

Okey, this is a well working tank IMO: No cyano, no need to clean anythink more than the window(and pumps and skimmer etc), corals, algae(the wanted ones) and fish with good health and so on.

No, I see no reason to add nitrate for the fish.

Like your example, I agree that cyano will appear in other nutrient levels then low nitrate. Sure. Sometimes it works well to lower the PO4 in cases where both NO3 and PO4 are high(over 20ppm NO3 and 0,1ppm PO4). But thats from our tanks here at the museum.

/ David

 

[Hans-Werner]

I worked with the aquaria in a public museum too until 2001.

In my eyes 0.1 ppm PO4 is not high, it is the upper limit of normal concentrations while 20 ppm NO3 is high. This holds also true for natural reef environments (at least nearly). The NO3 : PO4 ratio is 200 while in the reef it is around 2. If you would start lowering the nutrient concentrations in your tank with organic carbon dosing you would drive your corals into phosphate limitation (and in my eyes cause a cyano bloom this way). Do you have CO2-coral gravel-reactors for calcium supply?

 

[Sallstrom]

I worked with the aquaria in a public museum too until 2001.

In my eyes 0.1 ppm PO4 is not high, it is the upper limit of normal concentrations while 20 ppm NO3 is high. This holds also true for natural reef environments (at least nearly). The NO3 : PO4 ratio is 200 while in the reef it is around 2. If you would start lowering the nutrient concentrations in your tank with organic carbon dosing you would drive your corals into phosphate limitation (and in my eyes cause a cyano bloom this way). Do you have CO2-coral gravel-reactors for calcium supply?

Great! I work at a small public aquaria i Gothenburg, Sjöfartsmuseet Akvariet since 2009 Where did you work?

We have 4 different coral systems(total ca 45 000L), so we have 2 with calcium reactors, one with kalkwasser and one with Core7. So all the systems works in their own ways. This is due to limited budget and space.

Yes, I agree on that. Limitation of PO4 also can trigger cyano. In our bamboo shark + coral tank(26000L) we had low PO4(not detectable by Hanna Checkers) and NO3 around 20ppm(Core7, no calcium reactor). And started to get small patches with cyano. In this case we started dosing KHPO4 and ethanol. The cyano was gone two weeks later and after 4 month NO3 was down to 2-5 ppm. We kept the PO4 at 0,01-0,05.

The example from last post, I took that from a system with lion fish, moray eels, and Acropora etc, with NO3 at 20pp and PO4 shifting from 0,03 to 1,2 ppm. In this case we usually get cyano when PO4 goes up over 0,1 ppm. But if its the PO4 that does it I'm not sure. Maybe it has to do with changes in temperature or something else. In this system we have kalkwasser mixer.

/ David

 

[Hans-Werner]

I worked in the Jura-Museum in Eichstaett, Bavaria. It is a small natural history museum which has display tanks with reef fish and corals for comparision with fossil fish and corals. Other tanks show "living fossils" like Nautilus. I am sorry they show only one very bad image of a tank on their homepage. Total volume of all saltwater display tanks is maybe 10.000 l.

I think the cyanos in the lion fish tank may be connected to the precipitation of phosphate with kalkwasser.

There are at least 2 ways to run a tank without hair algae and maybe cyano problems and maybe much more ways to run into cyano blooms.

 

[Brew12]

Limitation of PO4 also can trigger cyano. In our bamboo shark + coral tank(26000L) we had low PO4(not detectable by Hanna Checkers) and NO3 around 20ppm(Core7, no calcium reactor). And started to get small patches with cyano. In this case we started dosing KHPO4 and ethanol. The cyano was gone two weeks later and after 4 month NO3 was down to 2-5 ppm. We kept the PO4 at 0,01-0,05.

Would you agree that increasing the PO4 allowed other more balanced algae/bacteria to out compete the cyano? Or do you feel the cyano went away through some other mechanism?

 

[Sallstrom]

Would you agree that increasing the PO4 allowed other more balanced algae/bacteria to out compete the cyano?

Yes, at least thats what I would guess.

But also that we in this case is able to hold the parameters very stable compared to smaller tanks(temp, pH, KH, NO3, PO4). In this tank we could also see on the corals that the PO4 was very low, they lost some colours. And I wanted to raise the dosage of ethanol to get the NO3 down. Therefor it was a must to add PO4.

/ David

 

[saltyfilmfolks]

No, I know a bit more about N-uptake of corals. I cite from the Sorokin book "Coral Reef Ecology", Springer, 1993:

"The saturation curves of consumption of P04, N03 and
NH4 by corals are similar to the Michaelis-Menten kinetic curve (D'Elia
1978; Webb and Wiebe 1978; Muscatine and D'Elia 1978). This indicates
that the consumption proceeds mainly via the enzymatic active transport
mechanisms. The threshold concentrations at which the consumption starts
are within 0.1-0.2Ilmoll-r, and that of Vrnax 1-2Ilmoll-l, which is the
same range as in the oceanic phytoplankton. The rate of consumption of
ammonia by corals was twice as much as that of nitrates in their ambient
concentrations (D'Elia and Webb 1977)."

I have to confess there are other results too but latest research says that natural nutrient sources (particular nutrients, plankton, ammonium) support coral growth while antropogenic nutrients, especially nitrate, are detrimental to corals.

"I show that P
consistently increases coral growth rates while N has variable, often negative, effects on coral
growth. The majority of this variability was explained by the contrasting responses of corals to
ammonium, which had negligible effects on coral growth, versus nitrate, which consistently had
negative effects on corals."

and

"Using meta-analyses, I show that N and P impact corals through two different
pathways. Nitrogen affects corals via direct effects on the endosymbionts within corals,
Symbiodinium, but the responses further depend on the identity of N provided. Nitrate tends to
impair coral growth and increase the chlorophyll content in Symbiodinium while NH4+ has
negligible effects on coral growth but still benefits the Symbiodinium within corals. In contrast, Penrichment
has no measurable impact on Symbiodinium populations but alters coral growth, most
likely via direct effects on the calcification process."

and

"Nitrate caused a significant reduction in calcification (Mean = -0.476, 95% CI = -0.583/-0.369)
while there was no effect of ammonium (mean = -0.037, 95% CI = -0.150/0.075) (Fig. 2.4a)."

and

"Our analyses show that nitrate tends to slow coral growth while ammonium has little effect
(Fig. 2.4). Further, the combined ammonium and P delivered by fishes may benefit corals more
than N-dominated anthropogenic sources as N-only enrichment drove decreases in coral
calcification (Fig. 2.1). Fishes may also be a source of particulate organic matter which corals
could ingest, further enhancing their growth rates (Meyer and Schultz 1985b)."

What corals are used in this study?

 

[Hans-Werner]

I am sorry but for the last cited article I don´t know exactly. The cited publication of D'Elia and Webb 1977 is not available in the net. I am quite sure they have taken SPS. Muscatine and D'Elia 1978 used Pocillopora and Porites.

 

[Lasse]

No, I know a bit more about N-uptake of corals.

Yes, I´m sure on that - but my point is that you in this discussion try to use argues that´s not the best to use. The concentrations you referred to only shows what have not been taken up not the uptake by itself. You can´t say – because NH4 is more available – it means that this species is most used. It could be so – but it can also be the total opposite.

I state that I believe that NH4 is the most preferred species – and I still believe in that but the way that you argue do not give any evidence for that.

I have read through the most interesting parts of the Doctor Thesis that you quoted in the last part of post 116. The in situ test they did gave more than one answer. Of three tested hard corals species – one of them they did not show any negative response either for NH4 or NO3. In the other two – they report that NO3 additive slow down the calcification rate. P additive did not do that. However - PO4 has always been believed to hinder the calcification process before. In one of them they noted a slower growth rate in the N enrichment compared with the P enrichment samples. But they could not say if it depended of slower growth for the N treated or faster growth for the P treated because the lost 7 of 8 controls.

The species they study was M. cavernosa, Siderastrea siderea and A. cervicornis



Back to the OP. I still believe that the key to understand the Cyanobacteria problem is to understand why the mats will be formed. The quote I published state that nitrogen deficiency will stop the building of proteins in the process forming new cells for the cyanobacteria, but it will not stop photosynthesis. Hence the photosynthesis will continue, and the produced sugar will be stored external. I.e. the mats will be constructed. This will be a gamechanger and the cyanobacteria can create a suitable microenvironment and use nitrogen from different sources in the anaerobic space between the mat and the substrate.

However, I think that every type of deficiency can start this process. Including phosphorus and trace metals – iron as one example. Even here – the cyanobacteria can create a suitable environment to capture phosphorus – either from organic matter below the mat or through released PO4 from the substrates. In the building up of more cyanobacteria cells – the mat (read sugar) is the storage for energy (read battery) – hence the change in size depending on light or not. And the mats can also play a role in capture light energy.

The challenge for us are to find the trigger – the substance that is limited for the construction of the cyanobacteria cells. Lucky for us – the most common trigger is probably N or P deficiency. In some occasion I also believe that adding NO3 can alter the possibility to get phosphorus out from the substrate. NO3 will stop the production of hydrogen sulfide – the trigger for breaking up the bonds between the metal and the phosphate molecule. In some occasion – the cyanobacteria gets the phosphorus from organic matter between the mat and the substrates. It can also have other biochemical pathways - as you outlined in an earlier post


If you get an up building of the cyanobacteria mats – my advises are still

Do you read low phosphate and high NO3 – test to add phosphate – do you read enough of phosphate and low NO3 – try to add KNO3

Do you have high concentrations of both PO4 and NO3 (and you are sure on this) – try to figure out what else you can have let to go to zero. In this case – a partial water change with a good salt can work.

But whatever you do – disturb the mats, suck them out, take down their biomass – just do not let them be because as usually, it´s under the cover the magic happens


Sincerely Lasse

 

[saltyfilmfolks]

I am sorry but for the last cited article I don´t know exactly. The cited publication of D'Elia and Webb 1977 is not available in the net. I am quite sure they have taken SPS. Muscatine and D'Elia 1978 used Pocillopora and Porites.

Thank you. It's an interesting observation when considering some corals , particularly soft corals seem to prefer higher nutrients along with more natural alk.

 

[Hans-Werner]

Lasse, I know a bit about plant and algal physiology. I have read some important textbooks on these themes. My approach to understanding corals comes from this side. If I read that uptake follows Michaelis Menten kinetics I know what that means.
There are several other studies from Monaco and Europe that anticipate the findings of the doctoral thesis from Florida. The guys in Monaco grow their corals in tanks with artificial lighting just as we do, but with natural seawater from the Mediterranean, for many years already.

My plea is just to be more open and try to view the processes in the tank as objective as possible and not to be prepossessed for something, not even theoretical knowledge. There are always two possible explanations, at least.

I think you overestimate the role of excretions in mat forming of cyanobacteria. I think mat forming simply means growth of Oscillatoria sp.. They grow in mats. Period.

 

[Lasse]

To come back to track again – can we have this theory of reasons for the constructions of mats as a starting point and try to either reject it, change it or accept it for now. My answer to the first question “What are the root causes of Cyano?” is – the moment they start to form the mats if the question is about the mat building cyanobacteria. The cyanobacteria cells will be in our aquarium all the time – but start to be a pest the moment they construct the mats. In post 107 Hans-Werner show a picture that´s rather like the ones I have found in aquaria before. Notable is that they lack heterocyst – it means – they can´t fixate nitrogen by themselves (fixate nitrogen = N2 - > NH4)

Sincerely Lasse

 

[Hans-Werner]

Notable is that they lack heterocyst – it means – they can´t fixate nitrogen by themselves (fixate nitrogen = N2 - > NH4)

Recent findings have shown that this does not hold true. Some cyanobacteria can fix N2 without heterocysts, for example by forming cells that do not perform photosynthesis or simply by fixing N2 at night when there is no photosynthesis and the cyanos consume oxygen. The formation of a slime coating could even make sense in this respect because it could protect the N2 fixing process from oxygen. Nevertheless I think that the Oscillatoria sp. we frequently find in aquaria grows in mats. I have found mats with 20 ppm NO3 and the "fertilization" with urea. There may be single filaments when the growth is very sparse but for the beginning I would assume that this Oscillatoria grows in mats if there is a substantial density of filaments, no matter what the nutrient conditions are. If there are no mats there are not enough filaments which means not enough cyanobacterial cells. Just watch without being prepossessed by any thoughts. After you are sure what you have seen it is time to look for theories.

This Oscillatoria sp. can move. Under the microscope you can see swinging movements but they can also perfom gliding movements. If you watch them thoroughly I think you will see that they do not disperse their mats at night but are really going into the bottom gravel to make use of high nutrient loads of interstitial water.

 

[Lasse]

I think you overestimate the role of excretions in mat forming of cyanobacteria. I think mat forming simply means growth of Oscillatoria sp.. They grow in mats. Period.

I´m not sure about this because you can always find this type of cyanobacteria in water samples without mats. And as the quote stated - about the role of excretions - its a well-known mechanism among benthic cyanobacteria.

But I will go further with this - I have a friend that´s doing her PhD thesis on cyanobacteria - time for a phone call

Hans-Werner - I do know very well your experiences and the huge impact you have done in the field of having stony corals in aquaria. To paraphrase poor American detective stories - I have figure out your surname
I do not discuss in disrespect - I discuss in order to learn and in order to put in my experiences into the discussion. The good things is that forum like this unite people with different experiences and different specialities and even in this field diversity is important and there can bee perspectives that have been overseen in the past.

As an example - then I first met David back in 2009 he was in the zero stage according how to handle NO3 and PO4. Everything else was ridiculous. However - his experiences during these years have get him to change his mind according to the best husbandry for the aquarias. And they are good - among the best I have seen and the goal for the rebuilding of Sjöfartsmuseet akvariet is humble - to create the best coral aquarium in the world.

After the invention of small blue bottles back in the 90:ties - the zero approach has been dominated for ALL coral husbandry. There has been a backslash to this the last years because it can create instable aquariums. Aquarium is not nature - it is its own ecosystem - with is own solutions.

As an example - we use organic carbon additives - how often do you pull vodka, vinegar or sugar over a natural reef? We use GFO – how often do you see this in nature?
Is it the whole truth that NO3 may not be good for corals – probably for some – but the theses that you linked to conclude that they had not seen any correlation with bad growth caused of NO3 in clams (chapter 5) , hence there are differences between organisms

According to phosphorus concentrations and coral health - IMO - you are totally right in your claims. I have run an aquaria with 1.45 mg/l in PO4 - with good thriving stony corals - I´m notorious for this in Sweden

However - I run my current aquaria with 0.05-0.1 ppm PO4 ande 0.5-10 ppm NO3

Sincerely Lasse

 

[Hans-Werner]

Lasse, thank you for the compliments.

However - his experiences during these years have get him to change his mind according to the best husbandry for the aquarias.

This means, he is now a proponent for higher nutrient concentrations you can find with a test kit, right? I made a similar change but only regarding phosphate. At first I thought phosphate must be very low but now I think 0.03 to 0.1 ppm are the best concentrations. Regarding N I think if you want to have a more transparent color of corals low N is ok.

I agree that the cyanos are always present in nearly all aquaria but I think the formation of mats is not mainly by the excretion of slime (which would mean at constant cell numbers) but by real growth with division of cells and the slime may play a role but a minor role. The formation of slime may be a process to accelerate the aquisition of nutrients for example by the induction of anaerobic conditions.

 

[Sallstrom]

This means, he is now a proponent for higher nutrient concentrations you can find with a test kit, right?

Yes, usually I try to keep nitrate between 1-5 ppm and phosphate around 0,03 in our coral tanks. Right now I let the nitrate go down a bit further in two tank, just to see if there will be cyano. In both tanks the NO3 has gone down very slowly, maybe 1ppm/month. So since I'm curious I wanted to see how these tanks will handle very low nitrate I'm ready to start dosing KNO3 if it comes cyano. The phosphate in these tanks is 0-0,01ppm when we meassure ourselves with Hanna Checker LR. Waiting for ICP-test results from Triton Lab. Nitrate is not showing any colour on the Salifert test this week.
So far no increase in cyano.

And since I'm curious, do you think we should try to dose KH2PO4 instead of KNO3 if we see signs of cyano?

/ David

 

[Hans-Werner]

David, I am no friend of dosing inorganic phosphate solutions. Inorganic phosphate tends to adsorb to substrate and rocks. The result is that the water is low in phosphate soon again and the cyanos grow on substrate and rocks. I like feeding more better. My suggestion is to feed the fish well to keep a bit of phosphate and remove nitrate (or surplus nutrients) for example with pellets in a pellet reactor. If feeding fish allone works well, even better. This provides the nutrients in the best form for corals, N as ammonium and phosphate as particulate phosphate which can dissolve in the water if low in phosphate.
I recommend this in German forums at least for 8 years now and finally got the scientific proof that I am right.

 

[Lasse]

Honestly - I can´t se the difference between orthophosphate from KH2PO4 and the ones produced by bacteria. Its the same orthophosphate form IMO, and the bacteria produced orthophosphate .
It will be precipitated in the same rate as the ones coming from KH2PO4 if there is metals present. My pH – I run the system for the time being between 8.10 and 8.40 – will precipitate calcium phosphate in some way regardless the source for the orthophosphate IMO. I do not know any other P species (in water) beside orthophosphate that will be taken up by organism using photophsynthesis. Have I missed anything?

However - I do not add any KH2PO4 to my aquaria - I have a DSB with reversed flow so I get the phosphorus I need from the bacteria breakdown in my DSB. I regulate the concentration with a GFO reactor (mix of Al and Fe)- The nitrate level I regulate through adding KNO3. My system "eat" NO3 in a high rate sometimes. I have also a low organic carbon addition - not in order to reduce nutrion levlels but to provide my filter feeders with bacteria food.

I have seen Cyanobacteria mats in aquaria with high NO3, in high PO4, in combined high NO3 and PO4. Record is 300 ppm NO3 and 8 ppm phosphate and small cyanobacteria mats at 5 meters deep (very weak light). In the same aquaria - with the same NO3 levels and PO4 levels , they disappear – one month later

I have seen (and I must say - most frequently both in fresh and saltwater) in low NO3 and low PO4 (both by them self and together)

Before - I have believed that the lack of cyanobacteria mats during night time has been vertical migration but I´m not sure of that any longer. The reason is that I have try to take up the mats below the surface of the gravel (there I thought they were) – but there was no sign of the jelly substance – not on the surface, nor in the sand and nor at the glass below the sand bed. It was gone away – but the next day – in the light – what did I see – guess.

My believe for the moment its that the jelly substances disappear during the dark period and will be formed by the cyanobacteria the next day again.

Sincerely Lasse

 

[MnFish1]

He's saying, keep your sand bed stirred. When you go to scrape the glass, turn the sandbed with a baster or something and let the tank filter out. Then change out filter floss or filter sock.

its interesting - I never touch my sand and have no cyano. My sand is not deep however.

 

[MnFish1]

Honestly - I can´t se the difference between orthophosphate from KH2PO4 and the ones produced by bacteria. Its the same orthophosphate form IMO, and the bacteria produced orthophosphate .
It will be precipitated in the same rate as the ones coming from KH2PO4 if there is metals present. My pH – I run the system for the time being between 8.10 and 8.40 – will precipitate calcium phosphate in some way regardless the source for the orthophosphate IMO. I do not know any other P species (in water) beside orthophosphate that will be taken up by organism using photophsynthesis. Have I missed anything?

However - I do not add any KH2PO4 to my aquaria - I have a DSB with reversed flow so I get the phosphorus I need from the bacteria breakdown in my DSB. I regulate the concentration with a GFO reactor (mix of Al and Fe)- The nitrate level I regulate through adding KNO3. My system "eat" NO3 in a high rate sometimes. I have also a low organic carbon addition - not in order to reduce nutrion levlels but to provide my filter feeders with bacteria food.

I have seen Cyanobacteria mats in aquaria with high NO3, in high PO4, in combined high NO3 and PO4. Record is 300 ppm NO3 and 8 ppm phosphate and small cyanobacteria mats at 5 meters deep (very weak light). In the same aquaria - with the same NO3 levels and PO4 levels , they disappear – one month later

I have seen (and I must say - most frequently both in fresh and saltwater) in low NO3 and low PO4 (both by them self and together)

Before - I have believed that the lack of cyanobacteria mats during night time has been vertical migration but I´m not sure of that any longer. The reason is that I have try to take up the mats below the surface of the gravel (there I thought they were) – but there was no sign of the jelly substance – not on the surface, nor in the sand and nor at the glass below the sand bed. It was gone away – but the next day – in the light – what did I see – guess.

My believe for the moment its that the jelly substances disappear during the dark period and will be formed by the cyanobacteria the next day again.

Sincerely Lasse

verkar mig - i en annan anteckning sa du högt nitrathämmande cyanobakterier i sjöar ....>?

Snöar det där än?