Lighting and correlation to bacteria/cyano/algae blooms?

[Dan_P]

Ok, Thank you for your observations. If you have the opportunity, could you please try to take a Spirulina photograph for me. I have only rarely found single spirals of Spirulina but never any mat or colony. I sometimes take images with a Sony APS-C mirrorless cam with kit lens but a smartphone should do the job too.

Here you can find a photograph of a single Oscillatoria sp. filament from me and some further microphotographs, some also with Oscillatoria spp. and other cyanos.

What do you think, how does the mat formation take place if not by growth and division of the cells and filaments?

Here is the edge of a small mat that was growing on green hair algae. It is a beautiful blue-green mat. I also have larger mats at the water edge or splash zone in my sump.

 

[taricha]

...but the main guy who does all their videos said he had two frag tanks plumbed to the same sump, but with different lighting units over each tank. So same filtration, same water, etc. He put 6500k bulbs over one and cyano all over it, but not on the other frag tank. Swapped the lights to the other tank, same thing. Took the 6500k bulbs off completely, cyano gone.

When I started I had a Hydra 26 over my first tank, and I seem to recall reading that you don't want a lot of red/green light, as that would "help" cyano/algae growth. Can't point that to anything specific since it was 3 years ago. I know my H160 from Kessil, which does an amazing job, is really purple light right now in "grow" mode over my sump.

Thanks for this - it aligns very well with what I was looking at in this post analyzing cyano absorbance spectrum

 

[Dan_P]

Ok, Thank you for your observations. If you have the opportunity, could you please try to take a Spirulina photograph for me. I have only rarely found single spirals of Spirulina but never any mat or colony. I sometimes take images with a Sony APS-C mirrorless cam with kit lens but a smartphone should do the job too.

Here you can find a photograph of a single Oscillatoria sp. filament from me and some further microphotographs, some also with Oscillatoria spp. and other cyanos.

What do you think, how does the mat formation take place if not by growth and division of the cells and filaments?

A recently photographed Spirulina mat growing on green hair algae.

The mystery of mat formation is around the cause of the rapid growth of cyanobacteria when seemingly nothing has changed in the aquarium. Here is a partial list of what seems to be universal facts about cyanobacteria in saltwater aquaria:

1-cyanobacteria are present in all aquaria
2-cyanobacteria filament density varies from scattered filaments only visible with a microscope to barely visible films to colorful colonies many centimeters in diameter to system-wide infestations
3-Most aquarist do not have microscopes, and likely those that do own one, do not regularly survey the surfaces of their system for microscopic life. As a result, the appearance of cyanobacteria is usually a surprise. Everyone thinks “something must have gone wrong” when in fact conditions may have been trending for weeks or months toward encouraging rapid growth.
4-The set of conditions, and it is definitely more than one thing or one ratio, that cause the cyanobacteria to progress from unnnoticed to noticed, or slow growing to rapidly grow and spreading are incompletely understood.

 

[taricha]

In my tank I keep conditions that are generally thought to encourage cyano mat growth. Lots of oganics/particulates that settle in the sand bed, low-flow across the sand, mixed spectrum lighting (I provide blues and a dash of red, and also get natural sunlight), and I never vacuum the sand, because I like the microfauna (many pods etc) and I have my favorite sand dwelling livestock .
So over the past several years, I have had cyano mats constantly. Observed them and the sand generally under the microscope quite a bit.
There have been two chemical conditions that I have intentionally created in the tank that halted and reversed cyano mat growth - without changing the background conditions favorable to its formation.

1) iron depletion - this was done by providing elevated NO3/PO4 and throttling down iron inputs to a minimum, while exporting macros etc.
Cyano receded with occasional slight reappearance and then would recede again.

2) Silica elevation - this has been a complete on/off switch. Above about a tenth of a ppm SiO2 (hanna checker) cyano receded, disappeared and stayed gone. It has not been seen in my tank in about 8 months. Now that I'm bringing Si back down from a high of 1.5-2.0ppm (0.13 last test) I saw the first tiny red cyano mat since I elevated Si (still not on sand - in a detritus pile collected in rock work). My sand has stayed full of gunk the whole time, cyano was just apparently excluded by mostly invisible diatoms.

I've been told this is "known" in the freshwater hobby. There's even a product (Nualgi) for managing "algae" - by which they mean cyano - in ponds that is just Si + trace elements.

If you think about it, 1) and 2) are quite likely the same mechanism or at least close cousins.

Are these "root causes"? No. But it seems it's it's possible to grow or exclude cyano mats on the sand without addressing things we'd think of as root causes.

(Edit: please excuse the fact I thought I was writing this reply in an entirely different cyano thread. [emoji4] )

 

[Dan_P]

In my tank I keep conditions that are generally thought to encourage cyano mat growth. Lots of oganics/particulates that settle in the sand bed, low-flow across the sand, mixed spectrum lighting (I provide blues and a dash of red, and also get natural sunlight), and I never vacuum the sand, because I like the microfauna (many pods etc) and I have my favorite sand dwelling livestock .
So over the past several years, I have had cyano mats constantly. Observed them and the sand generally under the microscope quite a bit.
There have been two chemical conditions that I have intentionally created in the tank that halted and reversed cyano mat growth - without changing the background conditions favorable to its formation.

1) iron depletion - this was done by providing elevated NO3/PO4 and throttling down iron inputs to a minimum, while exporting macros etc.
Cyano receded with occasional slight reappearance and then would recede again.

2) Silica elevation - this has been a complete on/off switch. Above about a tenth of a ppm SiO2 (hanna checker) cyano receded, disappeared and stayed gone. It has not been seen in my tank in about 8 months. Now that I'm bringing Si back down from a high of 1.5-2.0ppm (0.13 last test) I saw the first tiny red cyano mat since I elevated Si (still not on sand - in a detritus pile collected in rock work). My sand has stayed full of gunk the whole time, cyano was just apparently excluded by mostly invisible diatoms.

I've been told this is "known" in the freshwater hobby. There's even a product (Nualgi) for managing "algae" - by which they mean cyano - in ponds that is just Si + trace elements.

If you think about it, 1) and 2) are quite likely the same mechanism or at least close cousins.

Are these "root causes"? No. But it seems it's it's possible to grow or exclude cyano mats on the sand without addressing things we'd think of as root causes.

(Edit: please excuse the fact I thought I was writing this reply in an entirely different cyano thread. [emoji4] )

The school of thought that says “when you do “X” to prevent or cure a cyanobacteria infestation, a cyanobacteria competitor gets a boost and reduces nutrition that was allowing cyanobacteria to grow rapidly” probably likes example 2 a lot. Increase silica and presumably support diatom growth and othe Si loving organisms. The iron example is a bit more tenuous given that it is very difficult to prove the amount of iron in the system. But the notion of “feeding” the system with nitrate and phosphate aligns with the “help the competition” school of thought. Funny that the cyanobacteria that can out reproduce everything has competitors that can so easily be established and starve it. I think that I need more data

 

[Hans-Werner]

Thanks, Dan. Good photograph of Spirulina. Like mentioned I usually find only single short spirals of Spirulina.

I agree with your points. I think what solves a part of the "mystery" is that cyanobacteria are bacteria and exponential growth by cellular division can be very rapid. I think Taricha may be on the right track.

 

[Dan_P]

Thanks, Dan. Good photograph of Spirulina. Like mentioned I usually find only single short spirals of Spirulina.

I agree with your points. I think what solves a part of the "mystery" is that cyanobacteria are bacteria and exponential growth by cellular division can be very rapid. I think Taricha may be on the right track.

Would you and @taricha consider a “good” test of the Si addition hypothesis to be treating an actively growing cyanobacteria in 1 L of saltwater with silicate and observing whether or not it disappears? Maybe doing a similar test with ChemiClean might help define what “gone” means. Testing the iron limited hypothesis will be very tough or at least the ICP analytical cost would be expensive. I would prefer to show that adding a high dose of iron does or doen’t affect growth rate.

 

[Hans-Werner]

You would also have to make sure that the competing diatoms are present.

I am not sure but maybe a good trial would be to use some kind of chelator, maybe EDTA and look how cyanos react on this. EDTA may alter the iron availability, maybe. If it is a very simple and cheap setup just try what comes to your mind.

 

[taricha]

Would you and @taricha consider a “good” test of the Si addition hypothesis to be treating an actively growing cyanobacteria in 1 L of saltwater with silicate and observing whether or not it disappears? Maybe doing a similar test with ChemiClean might help define what “gone” means. Testing the iron limited hypothesis will be very tough or at least the ICP analytical cost would be expensive. I would prefer to show that adding a high dose of iron does or doen’t affect growth rate.

Two 1L containers. Split the cyano sample between the two, pull like 10ml of sand from a sand bed, split it between the two, then add SI to one of them. I'd aim for in the ballpark of 1-2 ppm SiO2.
Run it for 2 weeks or so.

 

[taricha]

Two 1L containers. Split the cyano sample between the two, pull like 10ml of sand from a sand bed, split it between the two, then add SI to one of them. I'd aim for in the ballpark of 1-2 ppm SiO2.
Run it for 2 weeks or so.

...oops. Add a 3rd identical container with cyano and sandbed that gets 1-2ppm SiO2 + 0.1-0.2ppm Fe added.
I don't know how likely this is, but if control bottle was cyano dominant, Si bottle had cyano recede/diatoms grow, and the Si+Fe bottle had cyano dominant or lots of both, then you'd know something very interesting.

 

[Dan_P]

...oops. Add a 3rd identical container with cyano and sandbed that gets 1-2ppm SiO2 + 0.1-0.2ppm Fe added.
I don't know how likely this is, but if control bottle was cyano dominant, Si bottle had cyano recede/diatoms grow, and the Si+Fe bottle had cyano dominant or lots of both, then you'd know something very interesting.

Is there a favored Si additive? Is chelated iron OK?

 

[taricha]

Is there a favored Si additive? Is chelated iron OK?

the ones I've used have been sodium metasilicate. I was worried about the chealation of the Iron too, but I (and another user) measured increased growth with Red sea trace colors Part C (Fe+ a few other trace light metals) and it's got EDTA according to the msds.

 

[Dan_P]

the ones I've used have been sodium metasilicate. I was worried about the chealation of the Iron too, but I (and another user) measured increased growth with Red sea trace colors Part C (Fe+ a few other trace light metals) and it's got EDTA according to the msds.

Thanks!

I wondered about chelation too. I am still trying to settle on a test to measure chelated iron. My Red Sea kit seems dead to iron gluconate and Hanna says their test does not detect chelated iron. For my experiments I rely on measurements not the appearance of an organism, so, I am kinda stuck right now.

 

[taricha]

...Hanna says their test does not detect chelated iron. For my experiments I rely on measurements not the appearance of an organism, so, I am kinda stuck right now.

I'm going to add that (along with Si) to the list of things Hanna says their meters are not approved for, but in reality they are as good or better any other hobby test kit.
Check a couple of posts out here from when I was messing around with the Hanna LR Fe meter.
Can it measure to near the range of natural Fe concentrations? not close. But it can definitely measure to well below the Red Sea recommended dosing levels.

 

[Dan_P]

...oops. Add a 3rd identical container with cyano and sandbed that gets 1-2ppm SiO2 + 0.1-0.2ppm Fe added.
I don't know how likely this is, but if control bottle was cyano dominant, Si bottle had cyano recede/diatoms grow, and the Si+Fe bottle had cyano dominant or lots of both, then you'd know something very interesting.

Should be interesting. A warm up test will be just increasing diatom population in a sample. If this works it could mean they are Si limited in my system.

 

[SaracensRugby]

@Dan_P you asked for a link to the articles I mentioned earlier about changing lights and cyano showing up, I found it. It was posted in one of the “Articles” here on the main page, about keeping notes.

https://www.reef2reef.com/ams/the-benefits-of-taking-careful-notes.610/

 

[Cory]

I thought this was interesting and may contribute to this thread:

 

[Dan_P]

I thought this was interesting and may contribute to this thread:

Did you survey the screens with a microscope? Cyanobacteria have the ability to change color. Both screens might be equally infested with cyanobacteria. What do you think?

 

[Cory]

Did you survey the screens with a microscope? Cyanobacteria have the ability to change color. Both screens might be equally infested with cyanobacteria. What do you think?

Thats someone elses ats. But iirc they said it was cyano and had problems getting hair algae to grow but when they switched lights the cyano was gone and hair algae grew.

 

[Dan_P]

Thats someone elses ats. But iirc they said it was cyano and had problems getting hair algae to grow but when they switched lights the cyano was gone and hair algae grew.

OK thanks.

The idea that light causes cyanobacteria growth has been around awhile and I wondered whether their was more details concerning the observation.

I am accumulating information and some lab data that makes me doubt most causes of cyanobacteria directly stimulate cyanobacteria growth. Growing bacteria in such a dense and localized mass must mean there is something fueling growth in that particular spot. I think @brandon429 considered this possibility in dealing with cyanobacteria growth on substrate.

Since cyanobacteria growth can also grow well on rocks, plastic and glass, this suggests to me that a combination of heterotrophic bacteria and organic matter is the starting point for all cyanobacteria mat formations. I am trying to demonstrate this outside of the aquarium environment.