Welcomed to APC! I have had similar looking algae blobs in my tank, but I have never known exactly what form of algae it is. I think you need to remove all of the blobs that you can, and probably reduce the light intensity. Those two plants don't require high light.
If you nitrates are at zero you may be encouraging the algae by starving the plants. What substrate do you have? Do you dose any fertilizers? Do you use CO2?
If you nitrates are at zero you may be encouraging the algae by starving the plants. What substrate do you have? Do you dose any fertilizers? Do you use CO2?