Thomas.pixner, Riesenvallisnerie Aquarium, CC BY-SA 3.0
key data
Attitude:
simply
Breed:
runners or cuttings
Size:
50cm to 200cm, 10cm to 5cm wide
Temperature:
18 – 30 ° C
pH:
6 – 9.5
GH:
up to 30 °dH
CH:
2 °dH to 20 °dH
Look
The Vallisneria (americana) gigantea, giant Vallisneria or also giant water screw is one of the frogbite family (Hydrocharitaceae) comes from Asia, more precisely from the area around the Phillipines or New Guinea and is particularly characterized by its broad, ribbon-like and strong green leaves. They are slightly serrated at the edges, tough and slightly rounded towards the end, but tend to be pointed. Since it can grow up to 2.5m tall, it floods the water in many aquariums.
distribution
Vallisneria multiply by runners under favorable site conditions such as nutrient-rich soil. A side shoot (stolon) forms from the stem or a rosette. This is therefore a daughter plant that is connected to the mother plant and grows away from it underground, but also growing above ground. After some time it forms roots and leaves, so that a new plant emerges. If it is big enough, you can separate it from the mother plant and replant it anywhere.
husbandry conditions
The Riesenvallisnerie is a fairly undemanding plant for larger aquariums, which should be fertilized regularly due to its strong growth. Otherwise, their leaves will become limp and wither. The aquatic plant is not very picky about the light conditions. It thrives in very little, as well as in sufficient or very good light, with the latter significantly promoting its growth. You don’t usually have to cut them back as long as they don’t block the incidence of light on other plants too much. Care should be taken with algaecides and other water additives, as the Vallisnaria does not tolerate copper and atrazine well. Copper in the water supply lines can also have a negative effect on the growth of the plant. The Vallisneria gigantea is particularly suitable as a background or border planting and quickly gives the aquarium the flair of an underwater jungle.
particularities
The Vallisnerie can also thrive in slightly cooler tanks and, because of its large, broad leaves, offers good protection for younger fish on the water surface. In addition, it is avoided by both snails and herbivorous (plant-eating) fish.
Occasionally it is pointed out that cryptocorynae and vallisneriae do not get along well in the same aquarium or next to each other due to allelopathy (excretion of special products of secondary metabolism by the plant to defend its location). However, this is not necessarily the case. The reason for this could be a large variability in the influence on growth due to the very complex allelopathic processes. Conclusive evidence for the growth-inhibiting interactions could not be found for these two plants.