I have built a number of ponds and water features. In so doing, I found that the biggest concern my customers had was about water clarity. With proper planning and foresight as to the location and type of the water feature, the size and amount of rock, the kind of filter media, and the addition of fish and plants, I was able to allay their fears. It's a lot less terrifying than it sounds.
Let's go through the stuff noted above. You can then proceed with your pond construction and enjoy the process, without worrying that it will be a pea-soup green bog at the finish.
Since I have found that siting of the water feature is of primary importance, take a quick look at the gallery to note different locations and conditions for the ponds, and we'll continue.
Very cool ponds!(click thumbnails to view gallery)