Pantanal Ludwigia

Ludwigia inclinata var. verticillata 'Pantanal' stops growing outright if its feeding lapses. Flowgrow is direct about that: nitrate has to stay in the 5 to 15 mg/l band and phosphate near 1 to 2 mg/l, and if the nitrate runs out the plant halts rather than slows. A shortage of iron shows up first as smaller, duller leaves and then as white new growth. That dependency accounts for most of the very difficult rating the database gives it. The plant is one of many forms of Ludwigia inclinata, set apart by finely divided foliage, and it comes from the Pantanal wetlands of southwestern Brazil. Grown above the waterline it is plain, with green ovate leaves; submersed it turns pink to red, which is the whole reason to keep it. Its conditions are specific. Light of at least 0.75 watt per litre, injected CO2 held around 25 to 40 mg/l, very soft water at roughly 6 dGH or below, and an acidic substrate with some peat in it. Flowgrow puts the optimum temperature at 24 to 28 °C and the pH 4.5 to 7. Under strong light the stems run vertically, which its relative 'Cuba' does not do, and it is the less robust of the two: where 'Cuba' can crowd a tank, this one rarely does. When the conditions hold it grows fast enough to need trimming on a schedule. Propagate by cuttings. Aquascapers use it mainly for red accents in soft-water layouts such as Tonina tanks, and it turns up only rarely in Nature Aquarium or Dutch styles.