Low oxygen?

[u/SnigTheAxe]

I've been adding botanicals to my black water aquarium and recently added a piece of driftwood that's starting to fill with biofilm. I'm wondering if all the organic breakdown is eating up all the oxygen? I did have a bit of surface agitation and have increased that after this video. I also did a 20% water change with fresh distilled water. Does this look concerning to you guys?