|How fast can I introduce new fish to the new Pond?
First, determine how many fish you can actually have. A good rule of thumb is one inch of fish per ten gallons of water. Even better, to allow the growth and increase in metabolism of the fish, two inches of fish per ten gallons should be considered "ideal" for best results. There are other formulas of some benefit, which relate the number of fish to square foot of surface area but these sometimes limit a person to have a single ten inch fish in ten thousand gallons of water.
How fast you introduce the fish is related to how efficient your filter is at growing beneficial nitrogen reducing bacteria. If you add all the fish at once, you'll see accumulations of nitrogen in the form of Ammonia, Nitrite and Nitrate. These are harmful to fish. If you add the fish slowly at first, you will see less of these accumulated nitrogens. Beneficial bacteria which use these forms of nitrogen will grow on the media in your filter and reduce the nitrogen. If the fish are added slowly, you will notice that the bacteria and the fish tend to keep pace and no harm is done.
Feed sparingly, and remember that Cheerios, as a temporary food source, offer little nitrogen for the fish, and therefore do not contribute to early-on nitrogen accumulation.