Getting fish home healthy, and their first day in the tank

Fish travel in a bag with water and air. Keep them warm and in a dark, closed bag or box, without shaking. Wrap the bag in winter, and do not leave it in a hot car in summer.

Go straight home. Every hour in the bag is extra stress for them.

The goal is for the fish to adjust gradually to your tank’s temperature and water. Simplest: float the closed bag in the tank for about 15–20 minutes to equalise temperature.

Then, if the shop’s water differs a lot from yours, gradually add small amounts of tank water to the bag over a few more minutes. Move the fish with a net and do not pour the bag water into the tank.

Some aquarists use slow water dripping for more sensitive species. Duration depends on species and the water difference, so ask when unsure.

You may dim the lights for a few hours so they settle. Feeding on day one is not urgent; offer a little or wait a day. Do not add everything at once: introduce new fish in several batches, as the filter needs to adjust to a bigger load.

Watch them: are they breathing steadily, swimming normally, eating? If something looks odd, ask us — take a photo and write.