It's not the first thread that goes like this
I've seen quite a few already. This algae tends to be VERY flexible and there is little accurate information on what's feeding it.
I did battle with it myself and managed to contain it in a very weak form on the substrate and spraybars.
To sum up *my* experience with it:
- grows in high and low current areas
- any light is enough for it
- it colonizes specific plants and dying leaf parts
- CO2 levels do nothing to kill it. CO2 is not a killer but a plant fertilizer
- cleanliness has nothing to do with it
- Otos and SAE will munch the weak, dying algae. They cannot clean it, don't buy them for this purpose.
- Amano shrimp will put a dent in it but they need to be starved
- ferts imbalance or lack will not weaken the algae, plants will die before it
- blackout will do the same as ferts
I do have a suspicion that it's resiliency stems from being able to get it's Carbon from carbonates/bicarbonates (kH) which are present in almost all waters except RO/DI. That's why it tends to grow faster if you increase water changes in an attempt to clean the tank.