Cyano / Spirulina + Hydrogen Peroxide Test

[SoCalVictor]

Hello all,

I've been dealing with a case of red cyano. Mine can form a very thick mat, both on rocks and sand bed.

I used the hydrogen peroxide test and with 1 ml in 2 cups of water, my sample did not react with it, which led me to assume I'm dealing with the spirulina version.

I have in the past spot treated this cyano by injecting 3% hydrogen peroxide right on it, inside the tank. The peroxide reacts with it and causes a lot of bubbling and the mat turns pink and often separates and floats to the top of the water.

Similarly, if I put a higher concentration of hydrogen peroxide in the 'test', for example, 2ml of 3% hydrogen peroxide in a 30 ml water sample with the mat, I get the bubbling reaction and the mat turns pink.

I understood spirulina not to react to hydrogen peroxide. Am I wrong about that?

thanks!

 

[shwareefer]

There is red spirulina?

 

[SoCalVictor]

Yes, I thought so?

 

[taricha]

Similarly, if I put a higher concentration of hydrogen peroxide in the 'test', for example, 2ml of 3% hydrogen peroxide in a 30 ml water sample with the mat, I get the bubbling reaction and the mat turns pink.

I understood spirulina not to react to hydrogen peroxide. Am I wrong about that?

The h2o2 test that some say distinguishes "cyano" from spirulina (really, it's also a kind of cyano - just not the more common oscillatoria-looking type) is based on spirulina reacting *less* to h2o2. I haven't seen that result confirmed.

I used h2o2 to distinguish between cyano and dinos - as the cyano bubbles significantly, but I had to go a good bit higher H2O2 concentration than 1mL in 2 cups to see bubble onset.

...left pic: samples, center pic: cyano, right pic: detritus with Large Cell Amphidinium Dinoflagellates hiding in it. Note how those strands could be interpreted as cyano or dino mucus. Let's find out which...
Add water until you have 100mL of sample, then add 5mL of common 3% hydrogen peroxide.
The cyano starts showing bubbles at 3mL or so, but by 5mL of H2O2 it should become really clear...

All cyano strands developed lots of bubbles. Even the tiny ones. Some start floating up....

(can click through the quote for the rest of the post)
In short, it's very likely you have a type of cyano. But I don't know if it spirulina or not. And even if it were spirulina and the test did distinguish that from the other more common type of cyano, you could still get the spirulina to react with peroxide if you push the concentration high enough.