Rotala indica

Rotala indica is distributed across tropical and subtropical Asia, including India, Japan, and Southeast Asia, where it inhabits paddy fields, shallow pools, and moist marshes. It is one of the most widely cultivated Rotala species in the aquarium hobby, appreciated for its manageable growth rate and the appealing warm-pink coloration it develops under elevated lighting and CO2. The submerged leaves are small, oval to rounded, and arranged in pairs along slender, often slightly reddish stems that form graceful arches in the aquarium. Unlike some of its more demanding relatives such as Rotala wallichii or Rotala macrandra, R. indica can be grown at intermediate skill level with moderate light and CO2 injection, producing at least partial pink-red colouration. It performs best in soft, slightly acidic water with a comprehensive fertilisation program. In aquascaping it is used primarily in the midground to add warm reddish tones and contrast against green plants. It pairs particularly well with Hemianthus micranthemoides, Eleocharis, and green Rotala species for layered depth effects.

Placement Best suited to the midground or background. Plant groups of 6–10 stems close together to create a dense, colourful mass. The plant looks most attractive when allowed to grow in slightly arching clusters.

Lighting Moderate-to-high lighting (45–75 PAR) is needed to develop pink-red colouration. Under lower light, the plant remains green. Photoperiod of 8–10 hours with quality LED or T5 fixtures is recommended.

CO2 & Fertilisation CO2 injection at 20–30 ppm significantly enhances both growth rate and red pigment production. Regular macro and micronutrient dosing, with attention to iron levels, produces the best colour. Low-tech cultivation yields only green growth.

Propagation Top cuttings of 6–8 cm root reliably within 7–10 days. The plant produces side shoots after trimming, each of which can be removed and replanted. Propagation is straightforward once stable conditions are established.

Trimming Trim tops every 2–3 weeks to maintain a tidy appearance and encourage bushy growth. Replant fresh tops; remove bare lower sections. Avoid letting the plant become too tall as the lower portions lose colouration in dense shade.