18. Wait 48 hours to add fish and plants*

 * It is best to use PVC piping 1/2 inch wider in diameter than the pump/pumps you are using recommend.  This drastically reduces the resistance/friction imposed on the water flow and gets you much closer to the theoretical performance of your pump.

*Depending on the type of water you have in your area and the amount of fertilizer that spills into the pond from any plants you put in - and the amount of water that runs into the pond from your house roof etc, it can take a few weeks for the pond to gain and hold onto its balance.  Fish can be put in 24 to 48 hours after you fill the pond but drastic swings in the balance of the pond runs the risk of killing some or all of them.  It is best to wait until the pond has remained clear and balanced before adding expensive or well loved fish.