1. Submersible pumps are generally limited to installations of 9 m2 (100 ft2) or less in areas that are drained, cleaned, and filled every few days in lieu offiltering. Maintenance and electrical safety are the primary concerns with these systems. 2. In remote systems, the equipment space should be as close as possible to the pool, and the floor elevation should be at least 600 mm (2 ft) below the lowest water level in the pool in order to provide a flooded suction forthe pump. 3. Filter systems are used to remove particulates from the water and return itto the pool (Figure530-19). 4. The fill/makeupsystem establishes the static water level (in conjunction with the overflow) and maintains the operatingwater level (Figure 530-20). 5. The overflow/drain system establishes the static water level (in conjunction with the fill system) and provides fordraining of the pools, piping, and equipment (Figure 530-20).