I use a mild 5% bleach solution of laundry bleach (1 part bleach : 19 parts water). I got the method from other internet sites. My anubias actually seem to be stimulated to produce more leaves from this process. I don't bleach the roots when I soak the plant and it removes almost all the algae after 3 minutes. I also rinse the plant thoroughly after a treatment.
I suppose I will try that if I can't find anything else that works. I don't want to disturb the root structure if I don't have too. Thanks for tip though.
I've sometimes taken one of the pipettes from a test kits and used it to spray either Excel or Hydrogen Peroxide directly onto a plant that was threatened by Green Algae.
Just one pipette at a time for the peroxide, maybe a second after all the bubbles had gone from the first shot. A full dose (for the tank) of Excel also got pipetted directly at the algae. After its been beaten back a bit you might try a soft toothbrush, but the stuff just seemed to disappear on its own. Recently did this with both to save a crypt.
I have successfully bleached Anubias barteri ''coffeefolia'' several times. The thicker leafed plants seem to be unharmed by this process. There are lots of internet articles proclaiming the same results. However, small or thin leafed plants have gone into shock and have taken weeks to resume growing. This is not a cure-all because if an imbalance is causing the algae, you will still have the problem and the algae will return. My anubias seem to be more susceptible to greenspot algae if they are in stronger lighting. After I bleached the anubias I moved them to a lower light location and the algae stayed away. The bleached algae appears as a white haze on the leaves for a day or two and then falls off, leaving clean leaves.