Drip acclimation: how to drip acclimate fish

What is drip acclimation?

Drip acclimation is a method of slowly mixing tank water into the container holding your new fish. Instead of floating the bag and adding a cup of water every few minutes, you run a thin tube from the tank so water drips in continuously. Over 30–60 minutes, the water in the bucket gradually matches your tank’s temperature, pH, and hardness. Fish adjust without shock.

When to use drip acclimation

Use drip acclimation when:

• Sensitive species — Discus, cardinal tetras, wild-caught fish, shrimp, and invertebrates often need gentler acclimation.
• Big parameter differences — Your tank’s pH or hardness differs a lot from the store or breeder.
• Long transport — Fish have been in the bag for hours; ammonia may have built up.
• Expensive or rare fish — Worth the extra time to reduce risk.

For hardy fish (e.g. guppies, platies, zebra danios) from a local store with similar water, float and partial water addition is often enough. Drip is the gold standard when you want to be careful.

What you need

• Clean bucket — Dedicated to the tank only; no soap residue.
• Airline tubing — Standard aquarium airline, 3–4 mm internal diameter.
• Knot or valve — To control drip rate (or use a purpose-made drip valve).
• Net — To transfer fish into the tank without pouring bucket water in.

Step-by-step: drip acclimation

1. Float the bag first (15–20 minutes). Turn off the tank light. Float the sealed bag on the water surface so temperatures equalise. Don’t add tank water to the bag yet.
2. Pour fish and bag water into the bucket. Open the bag and pour the fish plus all the bag water into a clean bucket. If the bag is very small, you can add a little tank water so the fish have room. Place the bucket below the tank water level so you can run tubing from the tank down into the bucket.
3. Start a siphon. Fill the airline tubing with tank water (suck on one end or submerge it to remove air). Place one end in the tank, below the water surface. Hold the other end above the bucket, then lower it — water will start flowing.
4. Set the drip rate. Tie a loose knot in the tubing, or use a valve, to slow the flow to 2–4 drips per second. Count the drips: too fast can still shock; too slow drags the process out. 2–4 per second is a good target.
5. Let it run 30–60 minutes. The bucket will gradually fill with tank water. After 30–60 minutes, the water in the bucket should closely match the tank. For very sensitive species or large parameter gaps, some keepers run it 60–90 minutes.
6. Net the fish into the tank. Use a net to catch the fish and release them into the tank. Do not pour the bucket water into the tank — it may contain ammonia from the bag, store water, or pathogens. Discard the bucket water.

Tips and pitfalls

• Bucket overflow — If the bucket fills before acclimation is done, remove some water (don’t pour it into the tank) and let the drip continue.
• Temperature — Keep the room warm; a cold draft can chill the bucket. You can float the bucket in the tank (if it fits) or place it on a towel.
• Light — Dim or turn off the tank light to reduce stress during acclimation.
• Drip too fast — If the drip is a stream rather than drops, tighten the knot or close the valve. Slow is safer.

Drip vs float: quick comparison

Float method: Float the bag 15–20 minutes, add a cup of tank water every 5–10 minutes, then net the fish in. Simpler and faster; fine for hardy fish and similar water.

Drip method: Continuous slow mixing over 30–60 minutes. Better for sensitive species, big parameter differences, or when you want to minimise risk. See our full acclimating fish guide for both methods.

After adding fish

Give fish time to hide and settle. Avoid feeding for the first few hours. Monitor water parameters — adding fish can cause a small ammonia or nitrite bump. Use App-aquatic to log tests and reminders.

Quick takeaways

• Drip acclimation = slowly mixing tank water into the fish’s container via a dripping tube.
• Use for sensitive species, big parameter differences, or when you want maximum care.
• 2–4 drips per second, 30–60 minutes, then net fish in — don’t pour bucket water into the tank.