Just finished a major deep clean and done a couple weeks of 70% water changes, things are looking way better now. Plants still got a bit of gunk on 'em but it's livable. The ladies seem to be enjoying it, even with me upping their feeds, tank's been steady as a rock.
Pic below's what it looked like before - super blurry, didn't even realize I never took a proper photo of it. Guess I was just too embarrassed at the time.