Cladophora aegagropila

Cladophora aegagropila (Moss Ball) is not really a plant, but a ball of algae, so it is a decorative exception from the rule about avoiding algae at all costs. It is normally found in shallow lakes, where the movement of the waves forms it into a sphere. In an aquarium it must be turned regularly to keep it in shape. C. aegagropila can be divided into smaller pieces, which become spherical with time, or which form a carpet, if attached to roots and stones. Protected in parts of Japan.
Height; 3-10cm Width; 3-10cm Light; very low-high Temp; 5-28'C
pH; 6-8.5 Growth; very slow Demands; Easy

Text from Tropica
Photo by Dusko Bojic

Microsorum pteropus

Microsorum pteropus is a water fern which should be grown on a root or stone, attached with fishing line until it has gained a hold. If it is planted in the bottom, do not cover the rhizome because it will rot. Easy to propagate by splitting the horizontal rhizome. A hardy plant which grows in all conditions. The black spots under the leaves are sporangia (reproductive organs), not signs of disease as many believe.
Height; 15-30 cm Width; 12-20 cm Light; very low-high Temp; 18-30'C
pH; 5-8 Growth; Slow Demands; Very Easy

Text from Tropica
Photo by Dusko Bojic.