It's not just that particular area, the both pieces of driftwood are outlined and dotted with this stuff. This tank has been empty for 10 years. No living creatures. Just added ammonia. Early on, I added Cycle, but I stopped that weeks ago.
I've not turned the light on, but the tank does get daylight through a shear covered window across the room. I've also had the biowheel filter, with filter and charcoal running the entire time. The water temperature is 80 degrees.
Ammonia is falling, close to 1ppm from a high of 5ppm. Nitrites are around 5ppm and Nitrates are in the 20ppm range. PH
is at 7.8, but I'm trying to bring that down to 7.0 or slightly below. It's at 7.8 despite the driftwood, and the use of RO
water mixed 3:1 with my tap.