@Cory and @Chris, thanks for the responses.
I have a decent green thumb when it comes to terrestrial plants, but aquatic plants are new to me. I have two tanks, a 20 Gal. tall with a small school of cherry barbs and a chinese algae eater (the clown-puke gravel in the pictures), and a 10 Gallon with only a smiling acara and a few trumpet snails (blue gravel). I have an anubias minima in the 20 tall, originally it was affixed to a piece of decor and not in contact with the substrate at all. I also have an anubias barteri 'wrinkled leaf' in the 10 gallon, which was affixed to a rock where the roots had some contact with the substrate. The A. minima in the 20 is in worse shape, if hardness has made the nutrients unavailable I suspect this is because it had no contact with the substrate and so had no nutrients. The A barteri was also looking bad but has bounced back better, looking almost healthy now, I think due to having roots already in the substrate. I had previously been fertilizing with aquavitro synthesis as I had bought this before easy green was available in Canada (where I live). I was dosing above the recommended rate because I never saw any nitrites or nitrates with the test strips (aquarium co-op brand of course). In both tanks I had black beard algae. When I moved the anubiases to the substrate, I also stopped fertilizing the water , supplementing only with root tabs, figuring that it would be a waste to continue if it wasn't available to the plants as I suspected. Now, the black beard algae has practically disappeared and the 20 is nearly spotless aside from a bit of green spot algae and black algae on the plants that the barbs keep at bay. Since I stopped fertilizing the water the 10 gallon has shifted from out of control black beard algae on the fake plants to mostly brown and green algae on the glass which I recently got the trumpet snails to deal with.
As far as lighting, the 20 gallon has a 20" easy LED set to 3 clicks, and the 10 had a 10" JC&P light set low, and has since been upgraded to an 18.5" JC&P light set as low as possible. Both tanks are lit 3 1/2 hours in the morning, and 6 in the afternoon/evening. If I recall correctly I also adjusted the light schedule a month or so ago, but they were receiving less light before, 4 hours and 4 hours I believe.
TLDR: the anubias in the 20 gal, relatively algae-free tank is doing the worst and the anubias in the more algae-prone tank is doing better. Nitrates and nitrites are null. I am not currently dosing fertilizer but when I was dosing heavily with aquavitro synthesis, nitrates and nitrites weren't showing either, and I also had black beard algae that has since disappeared. Lights are at low intensity and for 9.5 hours total per day.