While it's legal to build small ponds without a permit ... Some municipalities ban non-native fish like koi carp, amphibians like salamanders and newts, or reptiles like European terrapins.

If making a miniature pond has whet your appetite for wetland creation and you have a bit more space, you might wish to build a bigger pond ... doesn't need cleaning (different advice applies for fish ...

Ponds are probably the single most important ... Position plants and add oxygenators. If you want to add fish wait six weeks until the plants are established. According to The Royal Society ...