Things were going great until a few days ago. I was a day or two from flooding. But my HC in two spots just died overnight. It went from growing thick and green to just brown mush. Now those spots are growing rapidly and have consumed about a 1/3 of the HC in just two days.
All the other plants in the tank seem great and are growing quickly. I've aired the tank out for today to see if that will halt the spread. But I'm pretty sure the humidity levels are pretty good just based on past experience.
I took some macro shots and looks like tiny threads throughout the brown areas. I'm not sure what this is or what to do next. Anyone have any ideas?
Bummer!! I think that's mold. That looks like EXACTLY what took my s. repens and a ton of my UG. It moved pretty fast (relatively speaking) and just outright killed stuff. It also took out my 2 healthiest downoi. If you check out my fallen tree thread, I mention how I finally killed it, but that was under water. I'm fairly certain it was the anti-fungal API treatment I used.
I would have done what you did if I was still in DSM. Mix it with water and mist it. My tank was flooded, so I just dumped it in. I threw everything at it, but in the end mold is fungus, and I'm pretty sure it was the antil fungal that killed it. H2O2 and Excel had very little effect (and Excel will kill your HC in DSM anyway).