Tonina fluviatilis

Tonina fluviatilis originates from slow-flowing blackwater rivers and rivulets from Mexico to northern South-Americas, where it forms dense mat-like populations in shallow-water zones. It was first imported by Japanese aquarists who realised its beauty and suitability for aquatic layouts. Even though T. fluviatilis is still quite new in the hobby, it has been gaining increasing popularity and is now more and more frequently found in trade.
T. fluviatilis is the only species of the genus Tonina. It has a certain variability, and various location varietys are known whose habit differs a little. Some other stem-forming Eriocaulacea have erroneously been introduced to the hobby as Tonina species (for Tonina sp. 'Belem' and T. sp. 'Manaus', please see Syngonanthus macrocaulon and Syngonanthus cf. inundatus).

T. fluviatilis has quite special requirements for cultivation and is not a beginner's plant. First and foremost, this stem plant needs moderately soft water. A total hardness of around 5 or below is favourable. The substrate reactivity needs to be acidic. The plant needs a lot of light (1 watt per litre or more). CO2 injection is a must. Surprisingly, T. fluviatilis is not really finicky when it comes to the amount of liquid fertiliser, apart from an ample supply of iron and micronutrients. However, nitrate and phosphate levels should never fall to zero in any case.
Its special requirements sometimes cause planted tank keepers to set up an extra tank especially for T. fluviatilis and other plant with similar requirements (i.e. soft water and an acidic substrate, like Syngonanthus and Eriocaulon species etc.).

T. fluviatilis has an upright growth habit even under very strong light, however, from time to time it grows a lateral shoot on its stem. Its slow growth is the reason why faster-growing neighbouring plants pose the considerable danger of overgrowing it. Make also sure the plant isn't shaded. If it gets too high you can cut off the top part, whose stronger shoots may be used for propagation. If you want to propagate the plant, cut off lateral shoots and re-plant them in the substrate. It is recommendable to use only shoot tips of about 5 cm in length, as longer cuttings tend to grow roots on the lower part of the stem outside the substrate, which doesn't look nice. Shorter cuttings develop into more beautiful, healthier-looking stems.

Its uncommon, fresh greed foliage makes this plant a wonderful green accent for the middle- and background of an aquarium. Due to its moderate growth rate, its strictly upright habit and its adaptable height it is especially suitable for Dutch-style tanks.