Didiplis diandra, Peplis diandra

Didiplis diandra, also known under its old name Peplis Diandra, may be considered in aquascaping as an alternative to Rotala rotundifolia. Why? Because there are not so many species of red aquatic stem plants that have a small size of the leaf. It's well known fact that to create a sense of perspective in the composition, red aquatic plants as well as plants with smaller leaves should be placed in the background of the tank. Didiplis diandra and Rotala rotundifolia meet both of these criteria. The leaves of them are 2-3cm long and 3-4mm wide. But Rotala rotundifolia has a huge disadvantage because of its high growth rate. Stem of this Rotala can grow several centimeters per day. Consequently, trimming should be done more than once a week in order to maintain the composition and design of the aquscape. Therefore, I wouldn't recommend to use Rotala rotundifolia in aquascape, even though it can often be seen in different compositions and layouts.

Didiplis diandra doesn't grow as fast. But at the same time didiplis is more demanding aquarium plant. Didiplis diandra can be considered as a medium difficulty plant. It requires around 20-30 mg/l of CO2. At lower concentrations its leaves turn black and the plant stops growing. Color of the leaves greatly depends on the intensity of lighting in the tank. Intense red color of Didiplis can be achieved under strong light of at least 1 watt per liter. Under lower light, around 0.5 watts / liter, it has rich green color.

Didiplis diandra possesses one unique feature that makes it different from other species of stem aquatic plants. And that is its very short internodes of 5mm long. Didiplis also forms many side shoots near the top of the stem. Both these features result in the bushiest grow in the aquarium, especially at the top of the species group.

Didiplis is not very tolerant to trimming and often stops growing side shoots for a long time after being pruned. If you don't want to wait just cut the stem near its base and plant in the substrate.