Using cement in Hertfordshire is one of the traditional ways to build a backyard fish pond, and even with the advent of alternate techniques, concrete remains the superior way to construct a pond. Many homeowners are taking advantage of the pre-formed plastic ponds available at many home supply stores. This is probably the easiest way to build a pond. Unfortunately, many homeowners find the structure weak, and that it tends to crack and leak after a few years. A more popular way is to line the pond with EPDM synthetic rubber to form the pond. Unfortunately, the rubber material is susceptible to tears and holes. Both the pre-form and the rubber also have difficulty maintaining the proper pH level appropriate for fish. For this reason, homeowners still choose to use cement in Hertfordshire to build a pond that is both structurally sound and fish friendly. The first step is to plan out the size of the pond. It should be the right size for your yard, not too big as to overwhelm, not so small as to appear as a puddle. One trick is to cut black construction paper or tarp to size, and then place it where the pond would go and then take a step back. It will give a good rough idea of how the size of the pond will seem when completed. Once you have the size of the pond decided, lay out a string with some nice random curves to make the pond look natural. Stake the string in place, or trace the path of the string with orange marking spray. Then dig the pond. The minimum depth for a fish pond is three feet. This keeps your pond from turning into an instant smorgasbord for the local bird...