Quarantining New Fish
Always quarantine new fish. Quarantining your koi is important as with any fish as they can become susceptible to diseases when under stress and with a compromised immune system. While it may seem excessive to some to set up a large container to house fish temporarily, it is worth every penny to ensure your entire stock isn’t wiped out.
Make sure that your quarantine tank is cycled with a working filter (we typically have multiple sponge filters running in our quarantine tanks powered by one large air pump). An uncycled tank will quickly become toxic with ammonia and weaken your already stressed fish even further.
When you receive koi for the first time, the standard method of acclimating your new fish is to simply float the bag in the water and wait until the temperature of the bag matches the quarantine containment. Koi are quite hardy fish and being placed in clean water after a long travel in a likely polluted bag outweighs the potential parameter shocks; once the bag is opened the ammonia in the bag will become toxic quickly suffocating the fish inside. Never ever put the water from the bag into the pond or tank, from a big list of things to never do, this is near the top of that list.
While we do not recommend drip acclimation (we generally only suggest this for invertebrates); if you must for whatever reason, make sure to aerate the water with air stones and use some form of ammonia neutralizer (typically found in pond and aquarium dechlorinators). Failure to take precautions may lead to poisoning and death of your fish during the acclimation process or shortly after.