Water care for a Neon tetra: 21 to 25°C, pH 5.5 to 7
Neon tetra : It requires stable, soft and slightly acidic water with low nitrates. Change 20 percent of the water weekly, pouring slowly, as it is sensitive to osmotic and temperature shocks.
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🩺 The health watchpoints on this page are for information only: only a veterinarian can examine your animal and make a diagnosis.
In short: 3 to 4 cm as an adult, 60 to 80 L minimum for a school of 10, soft water between 21 and 25 °C. Gregarious and timid, it only settles in a tight school of ten or more, otherwise it pales and hides. A small tetra sensitive to osmotic shock: keep it only in a mature tank, in soft, slightly acidic water with subdued lighting.
The Neon tetra’s water: its real parameters
Temperature of 21 to 25°C, pH of 5.5 to 7, undetectable nitrites and nitrates under 25 mg/L: that is the contract. A drop-test kit (NO2, NO3, GH, KH, pH) beats any strip — and the nitrogen cycle, three to four weeks before any fish, is non-negotiable.
Water changes and tank upkeep
10 to 20% of the volume weekly, with water pre-heated to tank temperature: thermal shock stresses more than imperfect water, gentle substrate siphoning as you go and filter media rinsed in tank water, never under the tap: chlorine sterilises your filter.
Health: what stalks the Neon tetra
In the Neon tetra, watch for: neon tetra disease (Pleistophora), incurable and white spot disease after a temperature shock. But the golden rule holds for the whole tank — nearly all disease starts in degraded water or chronic stress, and you ALWAYS test the water before reaching for medicine. Well kept, a Neon tetra lives 5 to 8 years.
Frequently asked questions
What water parameters for a Neon tetra?
21 to 25°C, pH 5.5 to 7, zero nitrites and nitrates under 25 mg/L — checked with drop tests, not by eye.
How often should a Neon tetra tank get water changes?
10 to 20% weekly, water brought to temperature, filter rinsed only in tank water. Consistency beats volume.
The guides that apply to you
- Water Tests and the Nitrogen Cycle: The Essential Kit Before Adding Fish
Understand the nitrogen cycle and choose your water tests (strips or liquid drops): the guide to starting an aquarium without losing your first fish.
- Neon Tetra Disease: Symptoms, and Why It's Often Misdiagnosed
Discoloration, erratic swimming, weight loss: neon tetra disease worries fishkeepers, but a study shows it is often confused with a different, far more common and treatable illness.
- Hang-on-back or internal filter: which to choose for your aquarium?
Hang-on-back or internal filter for your aquarium? The hang-on-back frees up space and is serviced without hands in the water, the internal costs less. Comparison.
- Bacterial Biofilm on Aquarium Glass and Decor: Normal or a Sign of Trouble?
A clear, slightly slimy film often appears a few days after filling a new tank. Most of the time this bacterial biofilm is perfectly normal — here's when it actually deserves concern.