Frequently asked questions
Quick answers to the questions new discus keepers ask most often.
Are discus good for beginners?
They are not the easiest first fish, but a committed beginner can succeed. Start with a fully cycled tank, buy healthy tank-raised discus of at least 7–8 cm (3 in) from a reputable breeder, and be ready for frequent water changes.
How many discus should I keep together?
At least five or six. Discus are social, and a group spreads out aggression so no single fish is bullied constantly. Pairs and trios are the combinations most likely to end in trouble.
How big do discus get and how long do they live?
Adults usually reach 15–20 cm (6–8 in) across. With good care, discus commonly live for 10–15 years.
What water temperature do discus need?
Keep them between 28 and 30 °C (82–86 °F). This is warmer than most tropical fish prefer, which is why tankmates must be chosen carefully.
Do discus really need soft water?
Tank-raised discus adapt well to a range of water, typically pH 6.0–7.5 and moderate hardness. What they cannot tolerate is sudden change. Very soft, acidic water mainly matters for wild-caught fish and for breeding.
How often should I change the water?
For adults, change 30–50% at least once a week; many keepers do it twice a week. Growing juveniles benefit from daily or every-other-day changes. Always match the temperature and use a dechlorinator.
Why is my discus dark and hiding?
Darkening and hiding are signs of stress. Common causes are poor water quality, a recent move, bullying by tankmates, a sudden change in conditions or illness. Test your water first, then watch for other symptoms such as not eating or white, stringy faeces.
Can discus live with other fish?
Yes, with calm species that enjoy the same warm water, such as cardinal tetras, rummy-nose tetras, sterbai corydoras and bristlenose plecos. Avoid fin-nippers, aggressive cichlids and fast, greedy eaters.
Why are discus more expensive than most aquarium fish?
Discus grow slowly and need lots of food, warm water and frequent water changes while they are young. Producing high-quality colour strains also takes years of careful selective breeding.