It’s not Nocardia. I think it’s really most likely Microthrix but a Gram stain would really confirm it.


To me, those spaghetti like strands just scream Microthrix.


Very likely not to be nocardia. Nocardia (usually) looks more like a small plant or tree with the "strands" "branching" out across each other. Without doing a stain test you will give yourself a headache thinking too hard about it. Another easier method is to look at your plant numbers. A pretty good marker is that a low f/m and colder temperatures give microthrix a chance to thrive where most types of nocardia need a longer sludge age and higher temperature. pH could be used as a marker but I don't personally like to use that due to the fact that neither will instantly show up or instantly disappear on a high or low pH swing. Otherwise we would all just spike our pH in both directions and wash our hands of the issue.


M. Parvicella. I'm going to guess this was a sample of the mlss/ras? Look for spirocheates, they indicate low Do when in abundance with Microthrinx. Check SCADA trends to see how the Do are over night, and low flow. 2 of our tanks are like a standing breeding ground for these Fuckers.


Gram stain should tell you, at least narrow it down