To safely acclimate new fish (and invertebrate) puchases to your aquarium, use the following drip acclimation method.
1. Pour the fish and their shipping water into a fish-safe bucket or similar container. I use plastic containers made for reptiles and small animals with a snap-on top. They have a ready-made hole for an air line tube.
2.Set up a drip line by using a piece of air line tubing and draping it from the aquarium down to the container with the fish.
3.Start a siphon and allow the water to drip into the container. Regulate the flow by kinking the tube and wrapping a rubber band around the kink until about one drip comes out per second. I use a small air valve that allows me to easily increase or decrease the flow. Allow this to run until the water in the container is about double what it was when you started.
4.Carefully pour off most of the water until there is just enough to cover the aquarium fish when they are upright. Let the container fill again. This procedure slowly introduces the fish to your water and allows the temperature to equalize. It’s not a bad idea to add an ammonia neutralizer to the water, too. This will help reduce stress on the fish while they are adapting to your water.
5.Once the container fills again, the fish will be in about 90 to 95 percent your water. Carefully net the fish out and move them to their new home. Do not add the shipping water to your aquarium.