Pi Tetra

Protocheirodon pi is a miniature, highly distinctive tetra from the Colombian Amazon and upper Orinoco drainages, described in the 1980s and named for the π-shaped lateral marking that runs along the mid-lateral line. No other tetra displays this precise pattern, making the Pi Tetra instantly identifiable and highly sought after by serious collectors.

This species inhabits extreme blackwater environments with very low pH and near-zero hardness. It is a sensitive fish requiring dedicated blackwater tank conditions: very soft, acidic, warm water, heavy tannin use, and zero-to-minimal flow. It rewards these conditions with calm, elegant schooling behaviour in which the distinctive π markings of each individual create a hypnotically patterned group.

Feeding with micro-pellets, Cyclops nauplii, and baby brine shrimp maintains health. This is an advanced species for aquarists who have mastered blackwater husbandry.

Water: 25–29°C, pH 4.5–6.0, ultra-soft (GH 0–5, KH 0–2); blackwater with botanicals essential. Tank: 60 L minimum; blackwater species tank; dark substrate, dim lighting, minimal flow. Feeding: Micro-pellets, Cyclops nauplii, baby brine shrimp nauplii, and nano powdered food. Breeding: Rarely achieved; requires pristine ultra-soft acidic blackwater and fine live foods. Compatibility: Peaceful; keep with other tiny soft-water blackwater species only.