A partially in-ground pool provides the visual appeal of a fully in-ground pool with the low cost and ease-of-maintenance of an above-ground pool. In addition, sinking an above-ground pool several feet below the ground often makes it easier to manage pipes and pumps. Installing this type of pool is a straightforward process that can, when finished, bring a relaxing treat to the family while improving your overall property values.
After digging the hole for the pool, make sure the ground is free of protrusions like roots and rocks; the vinyl of most above-ground pools may not be thick enough to resist puncturing from sharp stones. Also, in addition to spraying the ground with herbicides to impede weed growth, consider applying broad-spectrum insecticides--pests like termites are attracted to vinyl and may start snacking on your pool liner. To keep the ground even, use a lawn roller to pack the dirt before laying the vinyl base.
As part of the installation process, add some sort of decking or a protective barrier like a fence around the pool. This will reduce the odds that small children or animals will fall into the pool and risk drowning. In addition, a solid deck around a sunk above-ground pool provides a platform for sunning and pool access that may be more useful than the standard ladders supplied with above-ground pools.
Partially-sunk pools are maintained the same way as normal above-ground pools: Clean the surface and vacuum the bottom and sides as needed to maintain water cleanliness, and provide chemical treatments as needed to control for bacterial growth. No normal routine maintenance is needed simply because the pool is partially sunk into the ground.
The metal sides of many above-ground pools were not designed to be sunk into the ground, so take steps to reduce potential corrosion. In addition, be aware that significant variation in ground temperature can lead to shifting pressures on the sides of a deeply sunk pool. Reinforce pool sides as necessary. In areas subject to freezing temperatures, make sure that any pipes or filters sunk into the ground can be accessed for drainage or repair from expansion damage.
Not all above-ground pools are equally capable of being sunk. Some pools rely on differences in pressure to keep their shape, for example, and the backfilled dirt may cause the pool sides to collapse if the pool is drained. Many pool manufacturer's warranties will be voided if an above-ground pool is sunk, so consider the potential risk before renting that backhoe.