Just acclimate them to their new home as you normally would, exchanging water in increments so all of the water quality parameters are adjusted gradually. Slowly introducing water from the new pond to the fish bags before eventually releasing them into their new home will enable the fish to smoothly acclimate to the new Ph and any other differences in the water. This adjustment to changes in water chemistry is just as important as adjusting to changes in temperature, if not more so.
With that said, let's face it: transporting your fish will impact their immune system. Some studies have shown that the fish’s immune system is completely suppressed for up to 72 hours after being moved. Other studies show that certain segments of the immune system remain suppressed for more than a week. Regardless of temperature, that lapse in immune function is an opening for the fish to break out with gill diseases and other issues. This is especially true if there are breaks in the integument or skin. By knowing the proper precautions to take, we can do our best to minimize the impact a move will have on your fish.
- If you are going to drive them, make sure that the bags are oriented side-to-side in the car so that the fish don't slosh forward and backwards.
- Try to store the bags (filled under pure oxygen) away from the light. For example, you could put those bags in boxes or black plastic bags.
- Try to avoid rapid temperature changes once the fish are in the bags.
- As much as possible, avoid breaks in the skin by netting, handling, or otherwise. Keep the skin as pristine as possible.
- When you put the fish in the pond, acclimate the temperatures as closely as you possibly can. If they come from ice-water, put them back in ice-water. Please understand that fish can come up in temperature twice as fast as they can go down in temperature. For example, dropping a fish from 60° to 40° is very stressful, whereas coming up from 40° to 60° is nowhere near as hard on the fish.
- For more expert advice about transporting koi in various seasons and climates, click here.