This aquarium is set up with potting soil in the bottom to grow Italian Val (Vallisneria spiralis).
Another alternative to adding potting soil on the entire bottom of the aquarium, is to add it to pots or other containers. This way you can pull the container out of the aquarium before removing plants and then re-pot.
Cyanobacteria often shows up in newly set up planted aquariums. It is typically a dark green in color, and can be removed from surface area in sheets. Cyanobacteria are bacteria that obtain their energy through photosynthesis. Cyanobacteria can cover sand, rocks, glass, and plants in the aquarium. Excessive growth can cover plants to the point where they can block light to the plants.
Cyanobacteria can cover any surface area in the aquarium, including live plants.
There is a simple remedy for eradicating cyanobacteria from the aquarium, the addition of erythromycin to the water and treat every other day for six days is normally all that needs to be done. Make sure there is no activated carbon in the aquarium system when treating with erythromycin.