Care at a glance
Temperature24–28 °C (75–82 °F)
pH5.5–7.0
Min tank15 gal (57 L)
Adult size5 cm
Lifespan5–7 years

A Serpae tetra is one of those animals that looks simple in the shop bag and turns out to have opinions once it is home. The Hyphessobrycon serpae Serpae tetra is a long-time favourite for a reason, but it has specific needs that generic "community fish" advice misses.

At a glance

Minimum tank15 gallons (57 L)
Temperature24 to 28 °C
pH range5.5 to 7.0
Adult size4 to 5 cm
Lifespan5 to 7 years
Group sizea group of 6+

Where it comes from

In the wild the Serpae tetra lives in slow, vegetated waters where cover is everywhere and currents stay gentle. Recreating that means planting densely, keeping the filter flow soft, and avoiding bright, open tanks that leave the fish exposed. Stable water matters more than perfect parameters.

Tank setup

Start with at least 15 gallons and a mature, cycled filter — see the ambulia guide before you buy. A sand or fine gravel substrate, a few driftwood branches and a carpet or mid-ground plant mass give the fish somewhere to retreat. Keep nitrates under 20 ppm with a weekly 34% water change.

Feeding

Feed a varied diet: a quality flake or micro-pellet as the base, topped up with frozen or live foods two or three times a week. Offer only what the fish clears in about 2 minutes, once or twice daily. Overfeeding is the single most common cause of water-quality swings.

A mistake everyone makes

Adding a Serpae tetra to a brand-new tank is the classic error. An uncycled tank spikes ammonia to 0.9 ppm within days and the fish pays for it. Cycle first, stock lightly, and let the group size build up gradually.

Good tank mates

Peaceful, similar-sized neighbours work best. Avoid fin-nippers and anything large enough to swallow the Serpae tetra. A planted community with the green water algae: the pea-soup bloom in the mix tends to settle quickly.

If you are new to this species

Start with the minimum 15 gallon tank fully cycled, hold the temperature at 24 to 28 °C, and feed a small amount once or twice a day. Resist adding tank mates in the first two weeks so the Serpae tetra settles without competition.