This Vallisneria prefers plenty of light and nourishment along with slightly hard water, but can manage quite well with less. Vallisneria americana var. asiatica has twisted green leaf that make a beautiful contrast when planted in groups. Its shorter leaves differ from most other Vallisneria-species and do not overshadow other plants in the aquarium. An easy plant that readily propagates via runners.
It does not do well in my tank where other plants flourish. My water is soft, I must add stones to have a GH of 5-6. It grows slow, grows runners, and algae somewhat attach to it. Substate is a mix of flourish and sand, with ferts in the water column.
In Las Vegas, 26 years ago, I had a 55 gallon tank that was thick with these great plants. It received about 2-3 hours of sunlight a day. It was a mixed community tank with no added fertilization and this plant flourished, sending runners out daily. I used to harvest it for the local fish store. I do think it prefers a slightly hard water with lots of light. Great pond plant also.