Question
We moved into our home last June.  There is a 6x8x2 pond in our backyard that when we moved in had several good size koi and many goldfish.  Over the winter the plants covered the surface.  In the last couple weeks it has warmed up and we removed the plants finding no koi and very few goldfish left.  We took our water to be tested, were told everything was fine.  We purchased 4 koi (about 3"long) and 12 goldfish. We scrubbed the bottom of the pond, did about a 40% water change, cleaned out our filter and added a quart of pond salt.  One day later, all but 1 koi had died as had many of the goldfish.  We immediately took the water back to the pet store and again were told our water was fine with a slight elevation of chlorine.  We just love koi and are really upset to lose these.  We'd like to get more but want to clear up what possible problem we may have.  Thanks

Answer
Hi Julie,

Thank you for your mail and sorry to hear all koi have died.
If the water is tested there should be other issues.
If the area surrounding the pond is fine, where I mean no threat from animals etc and no plants that can give debris that are a risk you maybe just had bad luck and put the new fish to soon in the pond.
As you may know small fish are more ease to die when put in the pond.
Best way to give from a distance is to first let the pond adjust for some days or week and then test the water. If the water is fine also do not forget that the pond has sufficient aeration.
If so you can buy some koi and place them for something like 30 minutes with the sack on the water to adjust to the temperature.
Then add water bit by bit at low tempo in to the sack.
After a few times you can release the fish.
Then you just wait and watch. Do not disturb the water or add salt or other products as this gives extra stress to the fish.
When all factors are ok there should be no problem.

Good luck and please keep me updated!

Regards,
Raf