Acclimating new discus: the drip method step by step (45–60 min)

What you'll learn from this guide

Acclimation is the most stressful moment for new discus — differences in temperature, pH and TDS between the transport water and your tank can be fatal if the transition is abrupt. This guide walks you through the drip method step by step (the standard procedure used by professional breeders), the materials you need (all for under €10, an RO estimate), and 5 common mistakes in the first hour after arrival.

📍 Scope: this covers the first hour (the drip procedure from arrival to transfer into the tank). For what comes after (hour by hour, the first 3 days, normal vs warning signs), see The first 72 hours with discus. For choosing the fish before you buy, see How to choose a healthy discus.

Why slow acclimation matters

Discus arriving from transport are in very different conditions from your tank:

An abrupt transition = osmotic shock + thermal shock + pH shock all at once = possible losses within 24–72 hours.

Drip acclimation solves this by adding your water gradually over 45–60 minutes.

Before the fish arrive — preparation

The day before:

• ☐ Confirm the tank is at 29 °C (84 °F) (check on a digital thermometer)
• ☐ Test for ammonia 0, nitrite 0 (API kit)
• ☐ Prepare a clean 5 L (1.3 US gal) bucket (used for the aquarium only)
• ☐ Prepare an airline hose with a valve (about 1 m / 3 ft)
• ☐ Prepare a clean towel and a net for the fish

On arrival day:

• ☐ Turn off the tank lights 1 hour ahead
• ☐ Cover the tank with a thin towel if the room light is strong
• ☐ Keep Seachem Prime on hand (emergency dechlorinator)

Materials you need — about €10 total (RO estimate)

Costs are an RO estimate (2026) — prices vary widely by country and brand. Use them as rough proportions, not absolute figures.

💡 Do NOT use buckets with detergent residue or towels with fabric softener — both are toxic to fish.

💡 Pre-made "drip kit" option: ready-made sets (hose + 2 valves + suction cups) exist for roughly €5–8. They work identically but cost about double the DIY version.

The drip method — step by step

Step 1 — Float the bag (15–20 min)

Goal: equalize the temperature.

1. Turn off the lights.
2. Float the sealed bag (with the fish) in the tank.
3. Wait 15–20 minutes.
4. Check with a digital thermometer: bag temperature = tank temperature (±0.5 °C / ~1 °F).

⚠️ Do NOT open the bag yet! Floating only.

Step 2 — Prepare the drip bucket

1. Put the bucket on the floor, next to the tank (at a lower level).
2. Open the bag gently and pour the contents (water + fish) into the bucket.
3. The bag water should cover the fish (about 3–5 cm / 1–2 in above their backs).
4. Tilt the bucket slightly to pool the water in one corner (so the fish have more room).

Step 3 — Set up the drip

1. One end of the hose in the tank (under water, near the surface).
2. Start the siphon by gently sucking the other end (or submerge the whole hose, plug one end with a finger, then move it).
3. Put the lower end in the bucket.
4. Adjust the valve to 1 drop per second (~1 ml/sec).

Check: count the drops — they should be 60–90 drops per minute.

Step 4 — Dripping (30–45 min)

Let the water drip until the volume in the bucket doubles.

Example: if you have 2 L (0.5 US gal) of bag water → when the bucket reaches 4 L (1 US gal), acclimation is complete.

Estimated time: 30–45 minutes, depending on the drip speed.

💡 Bonus: halfway through, remove half the bucket water and discard it (the old transport water is dirty). Keep dripping until the volume doubles again. This roughly doubles the pH/TDS acclimation.

Step 5 — Transfer the fish

Never pour the bucket water into the tank!

1. Using the net, move the fish one by one into the tank.
2. Discard the bucket water (down the sink, not into the tank).
3. Sterilize the bucket and hose for next time.

Step 6 — The first hours

• Keep the lights off for 24–48 h.
• Do NOT feed for the first 4–8 hours.
• Don't tap the glass, and don't invite guests for a "show."
• Observe discreetly, 1–2 hours apart.

Right after the transfer — what to check in the first 30 minutes

Once the fish are in the tank:

• ✅ They're all swimming (not lying on the bottom) — even if they hold still in a corner, that's OK.
• ✅ Breathing normally — 60–80/min, not gasping at the surface.
• ✅ No fish on its side or belly-up — a sign of severe shock.
• ✅ The water stays clear — no sudden cloudiness.

📖 What comes after the first 30 minutes — normal behavior vs warning signs hour by hour, when to feed, when to turn the lights on → see the dedicated guide The first 72 hours with discus.

5 common mistakes — avoid them

❌ Mistake 1: "I'll pour the bag water in, it's easier"

Why it's wrong: transport water holds concentrated ammonia, waste and possible parasites. NEVER add transport water to the tank.

❌ Mistake 2: "5-minute acclimation, I'm in a hurry"

Why it's wrong: osmotic + thermal shock often causes losses within 24–72 h, even if the fish look fine at first.

❌ Mistake 3: "I'll feed them right away so they settle in"

Why it's wrong: the digestive system is stressed. Uneaten food = ammonia. Wait at least 4–8 hours.

❌ Mistake 4: "I'll leave the light on to watch them adjust"

Why it's wrong: bright light raises stress. Lights off for 24–48 h after acclimation.

❌ Mistake 5: "I'll have the whole family come see the new fish"

Why it's wrong: lots of movement near the tank = prolonged stress. Keep it quiet for the first 2–3 days.

Special case — large parameter differences

If the seller's TDS differs a lot from yours (e.g. 400 ppm vs 150 ppm), you can't compensate in 45 min.

Solution: an extended drip over 2 sessions:

1. Session 1 (45 min) — drip until the volume doubles.
2. Place the fish in a quarantine tank with mixed water (50% transport + 50% your tank).
3. Session 2 (the next day) — 30% water change with fresh water from your tank.
4. After 3 days, move them to the main tank with a short 20-minute drip.

See: Discus quarantine for beginners and the advanced quarantine protocol (create EN equivalent before linking).

💡 Useful calculator: RO + tap water mixer to prepare water with the right TDS before arrival.

Stendker / Asian / local discus — acclimation differences

The "local breeders" row reflects the Romanian market; in your country, simply ask the seller which parameters their fish are kept at.

Final checklist — ready to acclimate?

Before the fish arrive:

• ☐ Tank at 29 °C (84 °F), confirmed on a digital thermometer
• ☐ Ammonia 0, nitrite 0 (API test)
• ☐ Clean 5 L (1.3 US gal) bucket ready
• ☐ Airline hose + valve ready
• ☐ Aquarium net ready
• ☐ Seachem Prime on hand
• ☐ Lights off 1 hour ahead
• ☐ Tank in a quiet spot (no TV, kids, pets)
• ☐ I've read this whole guide
• ☐ I have at least 1 hour free for the process

What to do next

📚 The mandatory next step: The first 72 hours with discus — what's normal and what isn't, hour by hour.

📖 The previous step: How to choose a healthy discus — pick well before you order.

🛡 Next level: Discus quarantine for beginners — a protocol before the main tank.

🧮 Useful calculator: RO + tap water mixer — prepare acclimation water with the right TDS.

🐠 Encyclopedia: Discus varieties — see each variety's specific needs at acclimation.

🚨 If a problem shows up in the first days: Quick visual diagnostic — check the symptoms and get instant suggestions.