The Elodea densa (Egeria Densa)​ from South America is a bunch of popular oxygenating pond plants that can also be used in indoor aquariums. Elodea is a genus of 6 species of aquatic plants often called the waterweeds, which are probably the most well-known of all aquatic plants. Thanks to its rapid growth it is the perfect plant for dealing with algae and this stem plant is also a popular oxygenator for aquaria and garden ponds. They are highly recommended for stabilising new setups. As with most stem plants, propagation is not complicated. Simply cut off the top or side shoots and replant them. In aquaria it may be necessary to cut the plant back often due to the speed at which it spreads. Plants are weighted and so can be simply dropped straight into the pond. There is no need for compost - covering base of plant with a few small stones/rocks may help it establish itself. For maximum growth the base of the plant can be placed in a small basket with aquatic compost.