🏠The Discus tank: 300 L, hardware and start-up
Discus : A tank of at least 300 L, 50 to 60 cm tall, for a group of 5 to 6 that establishes its hierarchy. Tankmates should be limited to calm warm-water species such as sterbai corydoras.
In short: 15 to 20 cm as an adult, 300 L minimum for a group of 5, very soft water between 28 and 30 °C. A gregarious, shy cichlid that forms a group hierarchy and gets outcompeted at feeding time if too harassed. The most demanding for water quality: very soft, acidic, at 28-30 °C, with an RO unit and frequent water changes essential.
300 litres minimum: why that number
For a group of 5+ Discus reaching 18 cm as an adult, plan 300 real litres — and remember a big tank is more STABLE, hence easier, than a small one: parameters drift slowly, leaving time to correct. At this volume, check your floor’s load rating and use a dedicated stand: a litre weighs a kilo, decor not included.
Hardware: filter, heater, lighting
The Discus tank’s technical trio starts with filtration — three to five volume turnovers per hour, a heater around 1 W per litre set to 28 to 30°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 Discus — the step every hurried beginner pays for dearly.
Frequently asked questions
What tank size for Discuss?
A real 300 litres minimum for a group of 5+ — below that, parameters drift too fast to catch.
Does a Discus need a heater?
Yes, about 1 W per litre set to 28 to 30°C, with an independent thermometer double-checking the thermostat.
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