All inground pools are created using a form of concrete to secure the base of the pool into the ground. Pools that lack a liner, however, are referred to as "gunite" pools, while pools with liners are "vinyl" pools.
Gunite pools are more expensive than the vinyl variety and typically contain areas of tile along the sides or bottom of the structure. Although more challenging to clean than a lined pool, a gunite pool is not limited by a liner and thus can be built in a wide variety of shapes and designs.
Use a pool net to remove any surface debris from the pool that has not been gathered up by the skimmer. Surface debris that is not removed will sink to the bottom after the pool is vacuumed and drained--creating extra work for the individual cleaning the pool.
Brush down the pool using a wire brush. Begin at the shallow end and brush the sides and bottom of your concrete pool in the direction of the pool drain to remove algae and dirt. You may opt to use a brush attached to a pole or brush by hand from within the pool. Both methods are equally effective.
Prepare your pool's vacuum by filling the vacuum hose with water to prime it. Dump any debris from your skimmer and attach the loose end of the vacuum hose to the skimmer.
Vacuum the concrete pool, beginning at the shallow end and moving the vacuum slowly along the bottom of the pool. If your pool contains a lot of bottom debris, you may need to dump the skimmer again midway through vacuuming to prevent overflow and loss of suction.
Drain the pool. This is necessary for stain removal and deep cleaning of the pool's tiles.
Clean the pool's tiles using any household tile cleaner and a damp washcloth or sponge. A light acid wash may be necessary if discoloration has appeared on the grout between the tiles.
Make a thick paste of granular chlorine and water. Apply the paste to any stains you find on the pool's concrete interior. Deeper stains may require pressure washing to remove.
Rinse your pool well with water and drain it. This is vital to remove any chemical residue left behind by the tile cleaner or acid wash.
Pressure wash the pool's interior to rid the concrete of multiple stains or intense discoloration. You may also opt to call your local pool care and supply store to request a full acid wash treatment of the concrete and tile. This will brighten the color of the pool and may be necessary for pools that have not been regularly maintained or have been left uncovered during winter months.