CONSTRUCTING MINIATURE POOLS
There are as many materials and methods for building pools as there are sizes and shapes. The depth depends on the requirements of the aquatic plants to be grown, and so does the location in sun or shade. Pygmy water lilies, for example, need all available sun, and at least ten inches of water—four inches for the container that holds soil and roots, eight inches above the crowns or growing points. Other miniature water plants are satisfied with much less.
One vitally important construction detail is that the sides of even the smallest tub garden be perfectly level, parallel with the water surface. Otherwise, there will be an unattractive expanse of bare wall at one side—one of those awkward errors that quickly catches the eye and spoils the whole effect.
Some pools are simply sunk flush with the surrounding lawn or other surface, without edging or coping of any kind. This can be messy and sometimes disastrous to plants when surface water collects and floods the pool during heavy rains. Extending the rim an inch or so above the surrounding area usually avoids this problem, but then the rim should be concealed with a coping of some sort—bricks and tiles in formal pools, well-arranged rocks, gravel, or flagstone paving in informal design.
Tubs and Other Containers
Attractive but relatively impermanent miniature pools can be improvised or specially planned with many kinds of containers—metal or wooden tubs made and sold for the purpose; half-barrels or half-kegs; discarded tanks, kettles, dishpans; even discarded sinks and laundry tubs. These last can be eyesores, we found out, if their ignominious origins are not kept carefully secret. Rubber-base paint is the only way we found to conceal the pristine white porcelain, and it was tricky to use so that it wouldn’t peel off. The rim at the top of the sink is an unpleasant giveaway that must be covered with something such as overhanging rocks. Finding a plug or stopper that fit the drainage hole wasn’t the least of our problems.
For the welfare of both aquatic plants and wildlife such as fish and scavengers, some containers need special treatment before they can be used, and some should not be used at all. Wooden kegs and barrels that have held oily substances such as gasoline, roofing compound, and wood preservatives can’t be cleaned sufficiently to be safe. Copper poisons fish; so do paints with oil or lead bases. Steel, lead, iron, and other metals should be protected against rust and corrosion with sound coats of rubber-base paint.
Containers freshly made of new wood (except white cedar) can be unhealthy for fish. Let them stand out in the weather for the winter, or season the wood by filling the container with water, slaking a chunk of lime in it for a few days, and rinsing well before using.
Prefabricated Pools
These are now available in metal or plastics of a sturdiness that varies with the cost, in a wide range of sizes and shapes. Many of them make lovely miniature pools which, because they’re small, are not necessarily calamities if they don’t last forever. Most have been designed after consultation with experts on fish and water lilies. And most are simply installed by digging a proper hole and setting them in place.