Rotala Wallichii

Rotala wallichii is easily told apart from other rotalas by its very thin, needle-like leaves arranged in whorls (verticils) along the stem. In strong light the shoot tips turn pink, red or wine-colored; from a distance the cluster looks like a soft, feathery brush.

Despite its beauty, it is a demanding plant. It wants soft, slightly acidic water, plenty of light, regular CO₂ and micronutrients. In hard water or in an aquarium without CO₂ it usually becomes spindly and disappears within a few weeks. For this reason it is not for beginners but suits planted aquariums with a CO₂ system.

• The stems are thin and brittle; they are buried 3–4 cm deep in small bunches of 3–5, held with tweezers.
• Leave about 3 cm between bunches so that the lower parts also get light.
• In the midground or background it creates contrast next to plainer green plants.
• Nutrient-rich active substrates that slightly acidify the water make things easier.

• Light: High; in weak light it stays green and the stems become thin.
• CO₂: Required; without regular, balanced CO₂, growth stops.
• Water: Soft (GH 1–8) and pH 5.5–7.0.
• Fertilizer: Micronutrients, iron above all, should be dosed regularly; when lacking, the tips fade.
• Trimming: Cut from the top. A cluster that has grown too old is renewed by replanting fresh tops.

It is propagated by top cuttings. The cut tops are replanted immediately; the main stem also produces side shoots. However, since old stems weaken over time, replanting the cluster with fresh tops every few months gives the best results.

• Pale, whitish tips: Iron deficiency.
• Tips curling and becoming stunted: Hard water or a CO₂ level that fluctuates during the day are the most common causes.
• Thread algae among the leaves: The fine leaves easily trap algae. Keeping the photoperiod at 7–8 hours a day and algae-eating shrimp help.
• Bare lower stems: When the cluster becomes too dense, the lower leaves get no light; frequent trimming and replanting are the solution.