Blue discus

1) Where they come from

Blue discus come from the Amazon basin—slow, warm, plant-choked backwaters with leaf litter, roots, and that “tea-colored” tint from tannins. In the wild they’re used to soft, acidic water and very steady conditions. That’s basically the whole discus game: stable, warm, clean.

2) Setting up their tank

If you’ve kept community fish, a discus tank feels like turning everything up: warmer water, more water changes, and more attention to calm vibes. Give them space and keep the environment predictable—discus get stressed easily and stress turns into disease fast.

• Tank size: I’d start at 55–75 gallons for a small group. Bigger is honestly easier because the water stays steadier.
• Group size: aim for 5–6+ if you can. Singles or pairs get picked on, and you’ll see more bullying.
• Temperature: 82–86°F (28–30°C). This is a big reason some “normal” community fish don’t work with them.
• Filtration: strong but gentle flow. I like big sponge filters plus a canister, or dual sponges on a bare-bottom grow-out tank.
• Substrate: bare-bottom is your best friend for grow-out and cleanliness. If you want sand, keep it thin and vacuum it often.
• Decor: tall driftwood, a couple broad-leaf plants (or fake plants), and open swimming space. They like vertical structure.

Water chemistry matters less than stability, but you’ll have an easier time if you’re not fighting your tap water. Tank-bred blues usually handle neutral-ish water fine, but they don’t forgive ammonia/nitrite at all, and they sulk if nitrates climb.

3) What to feed them

Discus are picky until they aren’t. Once they recognize you as the food-person, they’ll rush the glass, but new fish often take a week or two to really eat with confidence. Variety helps a ton, and small frequent meals beat one big dump of food.

• Staples: high-quality discus pellets or granules (I like small sinking ones so shy fish get a shot).
• Frozen foods: bloodworms, brine shrimp, mysis, and beefheart blends (messy, but they grow like crazy on it).
• Occasional: finely chopped seafood mixes, quality flakes (not my first choice, but handy).
• How often: juveniles 3–5 small meals/day if you’re growing them out; adults 1–3/day depending on your schedule and water-change routine.

4) Behavior and tankmates

They’re cichlids, but not in the “wreck the tank” way. More like moody, hierarchical, and easily intimidated. You’ll see pecking order stuff—lip-locking, shooing, cornering—especially in smaller groups or tight tanks.

• Best tankmates: cardinal tetras, rummy-nose tetras, ember tetras (in warm water), pencilfish, small peaceful plecos (careful), and calm bottom fish that tolerate heat.
• Avoid: fin-nippers (most barbs), hyper fish that spook them, aggressive cichlids, and anything that can’t handle 82–86°F long-term.
• Shrimp/snails: adults usually ignore bigger snails; shrimp often become expensive snacks depending on the fish.

I like keeping them with a decent school of small tetras because it makes the discus feel safer. A “dither” school can pull shy fish out into the open—just don’t overcrowd the tank and ruin your water quality.

5) Breeding tips (if you want to go there)

Discus breeding is equal parts awesome and maddening. A bonded pair will clean a surface, lay eggs, and guard like little helicopter parents. The fun part is watching the fry feed off the parents’ slime coat—one of the coolest behaviors in the hobby.

• Let pairs form naturally: start with a group of young fish and wait. Buying a “guaranteed pair” can work, but you’re trusting the seller’s eyes.
• Breeding setup: a separate tank is way easier. Bare bottom, sponge filter, heater, and a cone or vertical tile.
• Water: warm and clean. Many breeders use softer water for better hatch rates, but stable is the big deal.
• First spawns often fail: parents eat eggs, get spooked, or just don’t know what they’re doing yet.

6) Common problems to watch for

Discus problems usually start with stress: new tank, bullying, big temperature swings, inconsistent water changes, or a new fish bringing something in. The fish won’t always “look sick” right away—they just stop acting like discus.

• Not eating / hiding: often stress, bullying, or early illness. Watch the shy one closely.
• Darkening and clamped fins: a classic “I’m not happy” signal—water quality, temp swings, or parasites are common causes.
• White/stringy poop: can be diet stress, internal parasites, or just a fish that hasn’t been eating. Look at the whole picture before you start dosing meds.
• Hole-in-the-head / pitting: usually tied to long-term water quality issues and nutrition (and sometimes protozoans). Preventable with clean water and a varied diet.
• Gill issues (fast breathing, hanging near flow): can be ammonia/nitrite, high temp + low oxygen, or gill flukes—don’t guess, test your water first.