Black algae species

bobfloyd

Well-known member
Oct 16, 2014
45
Australia
Are we sure that black algae is Cyanobacteria? It's strikes me as having characteristics more similar to Audouinella. Cyanobacteria should be able to be nuked easily by chlorine or (expensively, not practical of course) via antibiotics.

Thoughts?
 

AUSpool

Bronze Supporter
LifeTime Supporter
TFP Guide
Sep 23, 2015
734
Brisbane, Australia.
I’ve just finished treating some black algae - I hope. I did a quick google and every industry site I visited avoid identification. I’m not sure Audouinella fits the bill, the hair like growth structure wouldn’t be very chlorine resistant and my black algae had more of a bulbous structure. Audouinella is a red algae, when you break the surface of a black algae you get a dark green mass rather than the reds, browns or backs of red algae. Black algae as I know it forms a fillamentous root system which would rule out the Cyanobacteria. The fillamentous root system and green flesh makes me think its a species of green algae although the structure does look a bit fungus like.
 

bobfloyd

Well-known member
Oct 16, 2014
45
Australia
There are different variants of Audouinella I believe, there is a form that doesn't have hairlike filaments but grows "flatter". A good test would be to get some and put it in Hydrogen Peroxide, it should then turn pink, then white, then die. This stuff prefers a 5ppm - 20ppm CO2 environment I believe, any idea what our pools typical warm weather CO2 concentration ranges are?
Can shock level granular chlorine sitting directly on it on the pool bottom do any harm to a light coloured pebblecrete surface? I reckon I could nuke mine that way if safe.