🏠The Danio tank: 80 L, hardware and start-up
Danio : A tank at least 80 cm long, covered since it jumps, with cool to temperate water. Avoid slow, long-finned tankmates, which it may harass.
In short: 4 to 5 cm as an adult, at least 80 L and an 80 cm long tank for a school, water between 18 and 25 °C. Tireless and playful, it races against the current in a school and may harass slow, long-finned tankmates. A cool to temperate fish often kept without a heater, but demanding in length: an 80 cm tank and a lid since it jumps.
80 litres minimum: why that number
For a group of 8+ Danio reaching 5 cm as an adult, plan 80 real litres — and remember a big tank is more STABLE, hence easier, than a small one: parameters drift slowly, leaving time to correct. This volume suits a sturdy standard cabinet — just verify perfect levelness.
Hardware: filter, heater, lighting
The Danio tank’s technical trio starts with filtration — three to five volume turnovers per hour, a heater around 1 W per litre set to 18 to 25°C, backed by an independent thermometer — built-in thermostats sometimes lie, and lighting on a timer at 8 to 10 hours a day: any longer and the algae win.
Substrate, plants and start-up
Nutrient substrate under fine sand or quartz, robust plants (anubias, vallisneria, Java moss) and wood to structure the territory. Then patience: a complete nitrogen cycle (3 to 4 weeks, nitrites back to zero) before the first Danio — the step every hurried beginner pays for dearly.
Frequently asked questions
What tank size for Danios?
A real 80 litres minimum for a group of 8+ — below that, parameters drift too fast to catch.
Does a Danio need a heater?
Yes, about 1 W per litre set to 18 to 25°C, with an independent thermometer double-checking the thermostat.
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