When feeding a bug to my Nep today, I noticed some spots on the leaves. And then when taking pictures, I noticed some light grey stuff on the soil. I noticed a small amount before and might have sprayed it with a sulfur-based fungicide, I can't remember for sure. But I saw a lot more today.
I grow it up in that glass block window. My initial thought was that the south-facing glass block window can magnify the light at certain points when it shines in, burning parts. And I was thinking that's what's turning the soil a dark burnt color.
Then I saw the grey stuff under the plant.
I would say the humidity is right around or just under 50%. I did let it get a little dry once a week or so ago, and I have started feeding it boxelders. Three or four in total.
Should I spray with my sulfur-based fungicide? Neem? Repot? It's been in the same pot and soil since July '09. I noticed the soil turning black in March '10.
Oh, and I water with RO water and it drains out the bottom.