How much might acost? Like almost any building project, there is no ceiling to what one can pay. But water gardening can certainly be regarded as an inexpensive pastime. An attractive, moderate-sized is within the reach of anyone. I would suggest, however, that you avoid the cheaper types of liner. Using polythene is false economy. If you do decide on a liner pond, it is only wise to buy the best, that is the heavier grade of Butyl rubber or PVC with nylon laminate. All these liners cost much the sameand theircost is similar to that of concrete (excluding the additional labour involved.) Fibreglass or plastic run at about three times the price of concrete and liner . Taken as an example, a modest sized pond, say 1.8 x 1.2 x 0.75 metres deep, would require a stretchable liner 3.3 x 2.7 metres or 0.76 cubic metres of concrete.
There is no point in giving the actual monetary cost of such a pond, since inflation is likely to make nonsense of the Figure within a short time. But one can give a compara-tive value. Such a medium-priced pond would cost roughly the same as a man’s sports jacket. Adding a submersible pump would more or less double the price. The cost of liners rises in proportion to their increase in size. The price of pumps increases by between 50 and 75 per cent as their output doubles. The addition of awould be your largest single cost. For the pond in question, one would need a at least 5.4 x 3.6 metres: 19.44 sq. metres. Pre-cast concrete slabs are among the cheapest kinds of paving units. Using 60 cm. Square slabs, one would need a total of 48 slabs, i.e. (19.44 – 2.16)-=-0.36. Roughly speaking, 50 concrete slabs would cost about the same as the liner and pump combined. So as a guide to the cost of a small patio pond, one could say it would be the equivalent of two sports jackets and one medium-priced suit. Clothes vary in price of course. But this comparision indicates the sort of money one is talking about.