Colorful discus fish in a professional planted aquarium
Care Guides

Discus Care Guides

Everything you need to keep the king of the aquarium healthy, vibrant, and thriving.

Discus Are Demanding — That's What Makes Them Worth It

Discus fish are widely considered the most beautiful freshwater fish in the hobby — turns out, they're not as difficult as their reputation suggest.  Just fascinating, intelligent and full of personality! Get the fundamentals right and they'll reward you with charm, stunning colors, and a tank that stops people in their tracks.

Essential

Water Parameters

Discus are sensitive to water chemistry. Getting your parameters dialed in is the single most important thing you can do for your fish.  Aim for stability within the ranges, not perfection.

Temperature82–86°F (28–30°C)

Discus thrive in warmer water than most tropical fish. Keep temps stable - long term temperature fluctuations outside of this can cause stress.

pH6.0–7.0

Soft, slightly acidic water mimics their Amazon River habitat. Aim for 6.5 as a sweet spot.  Stability over perfection.

Hardness (GH)1–8 dGH

Soft water is ideal. If your tap water is hard, consider RO water blended with tap.

Ammonia & Nitrite0 ppm

Any detectable ammonia or nitrite is dangerous. A fully cycled tank is non-negotiable.

Nitrate< 20 ppm

Keep nitrates low with regular water changes. High nitrates cause color loss and disease.

Water Changes25–50% weekly

Frequent water changes are the backbone of discus keeping. Use dechlorinated, temperature-matched water.

Water Parameters
Water Parameters
Nutrition

Feeding

Discus are omnivores with a preference for protein-rich foods. A varied diet keeps their immune system strong and their colors vivid.

Frequency3–5 times daily

Young discus need frequent small feedings to grow. Adults do well on 2–3 feedings per day.

Beef Heart MixStaple food

A classic discus diet. Homemade or commercial beef heart mix provides excellent protein and growth.

High-Quality PelletsSupplement

Reputable discus pellets like Sera Discus or Hikari are convenient and nutritionally complete.

Frozen BloodwormsTreat / conditioning

Great for conditioning fish before breeding. Feed sparingly — too many can cause digestive issues.

BlackwormsLive food option

Highly nutritious live food. Rinse thoroughly before feeding to reduce disease risk.

Fasting1 day per week

A weekly fast day helps clear the digestive system and reduces waste in the tank.

Feeding
Feeding
Setup

Tank Setup

Discus need space, stability, and the right environment to display their best colors and behavior.

Minimum Tank Size55 gallons

A single discus needs at least 10 gallons. A group of 6 needs a minimum 55-gallon tank.  Discus are social fish and do best in groups of 5 or more.

FiltrationHigh turnover, gentle flow

Discus prefer gentle currents. Use a canister filter or sponge filter. Aim for 4–6x tank volume per hour.

SubstrateBare bottom or fine sand

Bare bottom tanks are easiest to keep clean. If using substrate, fine sand is best — avoid gravel.

PlantsOptional but beneficial

Amazon swords, java fern, and anubias work well in warmer waters. Plants help buffer water chemistry and reduce stress.

LightingModerate, 8–10 hrs/day

Discus don't need intense lighting. Moderate light on a timer reduces stress and algae.

Tank MatesChoose carefully

Cardinal tetras, rummy nose tetras, and corydoras are classic companions. Avoid fin nippers and cold-water fish.

Tank Setup
Tank Setup
Health

Disease Prevention

Prevention is far easier than treatment. A clean, stable environment eliminates most disease risks before they start.

Quarantine New Fish4–6 weeks minimum

Never add new discus directly to your display tank. Quarantine in a separate tank to catch any illness.

Hex (Hole-in-the-Head)Watch for pitting near head

Caused by Hexamita parasite. Treat with Metronidazole. Linked to poor water quality and diet.

Ich (White Spot)Small white dots on body

Raise temperature to 88°F and treat with ich medication. Highly contagious — act fast.

Gill FlukesRapid breathing, flashing

Treat with Praziquantel. A common issue in newly acquired fish — another reason to quarantine.

Bacterial InfectionsFin rot, cloudy eyes

Usually secondary to poor water quality. Improve conditions first, then treat with antibiotics if needed.

StressRoot cause of most illness

Stable parameters, a peaceful tank, and a good diet are your best disease prevention tools.

Disease Prevention
Disease Prevention
Beginner Tips

Beginner Tips

New to discus? Here's what experienced keepers wish they'd known from day one.

Start with Juveniles4–5 inch fish are ideal

Young discus adapt more easily to new conditions than adults. Buy from a reputable breeder.

Buy in GroupsMinimum 6 fish

Discus are social fish. A group of 6+ reduces aggression and stress, and looks spectacular.

Cycle Your Tank First4–6 weeks before adding fish

Never add discus to an uncycled tank. Ammonia spikes are lethal. Be patient.

Test Your Water WeeklyAPI Master Test Kit

Don't guess — test. A liquid test kit is far more accurate than test strips.

Source MattersBuy from reputable breeders

Wild-caught or quality captive-bred fish from trusted breeders are healthier and easier to keep.

Be PatientThey take time to settle

New discus may hide and refuse food for the first week. Give them time, keep the lights low, and stay consistent.

Beginner Tips
Beginner Tips

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