How to Acclimate New Fish (Without Killing Them)
Sudden changes shock fish — go slow.
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Float and temperature-match
Float the sealed bag in your tank for 15–20 minutes so the water temperature equalizes. A sudden temperature swing alone can shock or kill a new fish.
Drip or add water gradually
Over 30–45 minutes, add small amounts of your tank water to the bag (or a container) so the fish adjusts to your pH and hardness gradually. Then net the fish into the tank — don't pour store water in.
Quarantine if you can
A 2–4 week quarantine tank prevents new arrivals from introducing ich or other diseases to your established fish. It's the single best habit for a disease-free tank.
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FAQ
How long should I acclimate new fish?
Plan on 30–60 minutes total: temperature float first, then gradual water mixing. Sensitive species like shrimp benefit from a slow drip acclimation.