A general FYI to everyone is that some antibiotics are also useful for clearing up algae which is what it looks like to me in the first picture.
Looks like algae to me. You keep saying the water is fine, but let me ask you what type of water test at a LFS would reveal algae? Different types of algae will grow differently and on different surfaces. Some of them like the brown silicate/ diatom kind are easy to wipe off surfaces (otocinclus love to eat this type). You haven't mentioned that this is on your driftwood too.
Keep in mind the leaves are driftwood are facing the light for hours a day with little movement.
HTH,
Walter
Walter
my anubias had the samething
i tried squirting flourish excel on the leaves and watered down bleach baths
it took out the algea away, but always came back
i dipped the anubias leaves in peroxide for 15 seconds and the algea never came back
i thought it was bba on my anubias leaves but was never sure
Quoting Aquaboogie,
"hydrogen peroxide?
Hi Aquaboogie,
Hydrogen peroxide off the pharmacy shelve is a mild bleaching and disinfectant and a viable alternative to household bleach solutions as a dip for killing black brush algae or other pesky algae that seem to like Anubias leaves as a substrate.
It can be used to temporarily increase the redox potential of aquarium water but that is both a different subject and something best not tried unless you know exactly what you are trying to accomplish.
Cyanobacteria can be killed by some antibiotics. I discourage using antibiotics unless the treatment is carried out in a separate container. No sense in exposing healthy aquariums to them since the drugs used in aquariums do not discriminate between the beneficial bacteria and the noxious ones. The results take longer and antibiotics are so much more expensive than any of the very effective OTC disinfecting oxidizers like Potassium permanganate, Sodium hypochlorite or Hydrogen peroxide.
Larry Waybright