Ruby Tetra Care Guide: Fiery Red Nano Schooler

This ruby tetra care guide explores the care of Axelrodia riesei, a tiny but intensely coloured tetra that has become a favourite among nano aquascapers. At Gensou Aquascaping, based at 5 Everton Park in Singapore, we find the ruby tetra to be one of the most captivating micro fish available, delivering vivid colour in even the smallest planted setups.

Species Profile and Natural Habitat

The ruby tetra originates from the Meta River basin in Colombia, where it inhabits slow-moving, tannin-stained blackwater streams shaded by dense forest canopy. It is one of the smallest tetras in the hobby, reaching a maximum size of just 1.5 to 2 centimetres. Despite its diminutive stature, the ruby tetra possesses a rich crimson-red body colouration that intensifies under the right conditions. It was described in honour of the ichthyologist Herbert R. Axelrod.

Tank Size and Nano Setup

Ruby tetras are ideal candidates for nano aquariums, with a group of ten or more thriving in tanks as small as 30 litres. However, a 40 to 60-litre tank provides more stable water parameters and additional space for aquascaping. The tank should be densely planted with fine-leaved species such as Rotala, Micranthemum, or mosses. A dark substrate enhances their red colouration dramatically. Driftwood and Indian almond leaves complete the blackwater aesthetic and provide beneficial tannins.

Water Parameters and Conditions

Ruby tetras require soft, acidic water to display their best colour and maintain good health. Aim for a pH between 5.0 and 6.5 and a general hardness below 8 dGH. Temperature should be kept between 24 and 28 degrees Celsius. In Singapore, where tap water can be moderately soft, blending with reverse osmosis water and adding botanical extracts can help achieve ideal conditions. Filtration should be gentle, as these tiny fish are not strong swimmers. A small sponge filter is often the best choice.

Feeding Ruby Tetras

Due to their small mouth size, ruby tetras require appropriately sized foods. Crushed high-quality flakes, micro pellets, and powdered foods work well as staples. Live and frozen baby brine shrimp, micro worms, and vinegar eels are excellent supplementary foods that bring out the best colour and condition. Feed small amounts two to three times daily, ensuring the food particles are small enough for these tiny fish to consume comfortably.

Behaviour and Schooling

Ruby tetras are shy, peaceful fish that rely on the security of a school. Keeping them in groups of at least ten, ideally fifteen or more, encourages natural schooling behaviour and reduces stress. In a well-planted tank with subdued lighting, they become bolder and display more actively. Males may spar gently with each other, flaring their tiny fins in brief displays. Their small size and gentle temperament make them unsuitable for community tanks with larger or more boisterous species.

Suitable Tank Mates

Choose tank mates with care given the ruby tetra’s diminutive size. Ideal companions include other micro fish such as Boraras species, pygmy Corydoras, small rasboras, and dwarf shrimp like Neocaridina or Caridina. Otocinclus catfish are also compatible. Avoid any fish large enough to view ruby tetras as potential prey. In a dedicated nano biotope, a species-only tank can be the most rewarding approach, allowing you to observe their natural behaviour without competition.

Health and Maintenance

Ruby tetras are delicate fish that are sensitive to water quality fluctuations. Consistent maintenance is essential, with small, frequent water changes being preferable to large, infrequent ones. Change 15 to 20 per cent of the water twice weekly for optimal results. They are susceptible to common tropical diseases when stressed, so stable parameters and a calm environment are the best preventative measures. In Singapore’s warm climate, ensure the tank does not overheat during particularly hot days.

The Ruby Tetra in Your Aquascape

Few fish deliver such intense colour in such a small package. The ruby tetra transforms nano planted tanks into living jewel boxes, with their crimson bodies glowing against green foliage and dark wood. For aquarists who appreciate the art of small-scale aquascaping, this species is a must-have. Visit Gensou Aquascaping for advice on creating the perfect nano setup to showcase these remarkable little tetras in all their fiery glory.

Related Reading

• Bentosi Tetra Care Guide: Ornate Fins and Subtle Elegance
• Black Neon Tetra Care Guide: Understated Elegance
• Long-Fin Black Neon Tetra Care Guide: Flowing Dark Elegance
• Black Phantom Tetra Care Guide: Dark Elegance in Schools
• Black Skirt Tetra Care Guide: Bold Shape and Easy Keeping