Drip acclimation: settling new fish in safely
Pouring a freshly bought bag of fish straight into the aquarium is still a risky habit: the water chemistry at the store or supplier's end often differs sharply from the destination tank, and too abrupt a shock leaves fish weakened for days. A review by Luís Sampaio and Carlos Freire, published in 2016 in the journal Fish and Fisheries, details how transport water quality deteriorates with trip duration (falling pH, rising ammonia) and how much that physiological stress weakens fish on arrival (study on Google Scholar). Drip acclimation is the safest way to soften that shock. Find all our transport gear in the travel and safety section.
Why floating the bag is not enough
Floating the bag for ten minutes only equalises water temperature, not its chemistry: pH, hardness and nitrite levels can still differ widely between the bag and the tank. For a hardy fish on a short trip, that step alone is usually fine; for a long journey, a discus, shrimp, or any already-stressed fish, it falls short.
What you need for drip acclimation
- A length of flexible airline tubing and a flow-control clamp.
- A clean bucket, kept only for fish, placed lower than the aquarium's water level.
- A suction cup to hold the tubing's end on the tank's rim.
Step by step
- 1. Pour the bag, fish and all, into the bucket, keeping the original water.
- 2. Start the siphon between the tank and the bucket, then set the clamp to 2 to 4 drops per second.
- 3. Let it run until the water volume in the bucket has doubled, over 45 minutes to an hour depending on how sensitive the species is.
- 4. Net the fish across into the tank, never pouring the bucket's water into the aquarium.
Special cases: shrimp and sensitive fish
Shrimp and snails, very sensitive to sudden parameter shifts, deserve an even slower acclimation, spread over an hour and a half to two hours. After any transport, keep an eye on your water tests for a few days: a nitrite spike is still possible if acclimation was rushed.
Frequently asked questions
Should the tank lights stay off after introducing new fish?
Yes, dim or off lighting for several hours helps a newcomer settle and recover from transport stress, especially after moving an aquarium or a long trip.
Is drip acclimation worth it for a routine pet store purchase?
It is worth doing whenever the trip runs past thirty minutes or the species is known to be sensitive. For a very short trip with hardy fish, floating followed by gradually adding tank water is usually enough. All our acclimation advice is gathered on the fishkeeping hub.
This guide is part of Planète Pets’s Fishkeeping universe. Our advice is general in nature: for any health concern, your veterinarian remains the only reference.