Acclimatising Your Fish

Acclimatising your fish |
Acclimating fish to your water conditions

Whether you’re introducing fish to your main tank or a quarantine tank, the basic process should always be the same: exposethe fish to as gradual a change in water chemistry as possible. A few fish have evolved to handle big changes in water chemistry (brackish water fishes, for example) but most react very badly to suddenchanges in pH, hardness, salinity, and temperature. Whether the fish is going from worse to better water conditions is irrelevant here, so don’t assume the fish will be happy to get out of the dirtywater in the bag and into a proper aquarium because it doesn’t work quite like that. Fish adapt over time to even bad conditions, and will need to re-adapt to the better conditions in your aquarium.The traditional way to introduce new fish into the aquarium is to place the bag containing the new fish into the aquarium unopened and leave it floating for 20-30 minutes so that the temperatureinside the bag matches that of the water in the aquarium. The bag can then be opened and the fish gently poured into the aquarium. The problem with this method is that while it eliminates the problems oftemperature change, it does nothing about water chemistry. So a common solution is to use a needle to pierce the unopened bag half a dozen times while it is floating it in the tank. Water will diffusein and out of the bag, gently changing the water chemistry inside the bag to that of the water in the aquarium. This approach can work very well, but the downside is that water from the bag gets intothe aquarium, dumping the load of ammonium that accumulated while the fish was being transported and potentially allowing in any swimming parasites that were in the retailer’s tanks, such aswhitespot.

A cleaner method is to half-fill a bucket with water from the aquarium and float the pierced bag in that. This will allow the fish to adapt to changes in water chemistry and temperature...