Possible cyanobacteria occurring

[Gowalkitoff]

I need some advice please. I believe I am having patches of cyanobacteria appear throughout my 120 gal tank.  I do not know why.  I have tons of flow; two eheim canisters for 150 gal and 90 gal.  Does anyone have any ideas?  I have done extensive reading about this and can not deduce a cause.  Thanks.

[Anubias]

Higher oxygen levels will reduce the spread. If you have plants, a stable CO2 level and good growth should keep it in check. A complete blackout for 4 or 5 days will kill it. So will erythromycin -if you can find it.

[Gowalkitoff]

Thank you