Hygrophila corymbosa "Angustifolia": a fast-growing background plant.

Hygrophila corymbosa “Angustifolia”: a fast-growing background plant.

via The Wet Spot Tropical Fish

Growing in emersed conditions, Hygrophila corymbosa “Angustifolia” can reach over three feet in height. In the aquarium, this Southeast Asian specimen will grow out of the aquarium if given the chance, producing blue-violet flowers and a thickened, woody stem. Emersed, it will often shed the lower submersed leaves. Because of its height, H. corymbosa is often used as a background plant. The long, thin, lanceolate leaves are light green in color and provide an elegant contrast to the darker, rounder foliage found on Anubias species while also complimenting Cryptocoryne species such as C. balansae or C. retrospiralis.

Lighting conditions should be medium to high, while substrates can range from gravel enriched with root-tabs, to soil-like media such as Aquasoil by ADA. While some sources infer that H. corymbosa has some difficulty rooting or transitioning to submersed growth, this author has not found that to be the case. Dosing with Seachem’s Flourish Advance (which contains phytohormones that help cuttings root), specimens are able to quickly form robust root systems that anchor it in place. While CO2 is not necessary, it is recommended to promote the fast growth of this plant which will quickly absorb nitrates in the water column and ultimately help keep the water clean and your fish happy.