When going to koi shows the natural human reaction is to buy koi. Why not? After all, there is such a wonderful selection of beautiful fish that should be swimming in your own pond, and the prices are right! So, you shop and buy, and the dealer will pack the fish in plastic bags filled with pure oxygen, tied up with a rubber band. Now, when you arrive home, what do you do? According to most koi hobby lore, we have been adding pond water to the bags in way of acclimating the fish to your own pond water chemistry…. THAT’S THE BAD NEWS….
Never add pond water to the bag! Simply by opening the bag, some of the carbon dioxide will be released into the air and the loss will result in an instant increase in pH inside the bag. As the pH rises, so does the lethality of ammonia in the water.
According to Norm Meck, the Water Quality expert for the AKCA’s KHA program, when a fish is contained inside the double-wrapped plastic bag for any length of time its own exhaled carbon dioxide will actually combine with the water producing carbonic acid to lower the pH in the bag. The ammonia being produced by the fish’s respiration will then result in a harmless ammonium product! THAT’S THE GOOD NEWS.
When the new (pond) water is added, the pH is immediately raised, by the pH in the pond water! The first thing happening to the fish is STRESS. Ammonia burns the gills, much like chlorine, and it takes up to eight months for it to manifest in a fish death, long after you have forgotten about acclimating this fish to the pond water…. Besides, that’s what you were told to do, right? Sometimes we are given the wrong information unintentionally.
So, it is fine to float the UNOPENED bag on the pond (or quarantine tank) for up to 30 minutes to adjust the water temperature, and then, without adding any pond water, lift the fish out of the bag and directly into the clean water. Throw away the water from the bag. Never put any of it in the pond. Your fish will thank you…. Eight months from now!