Section 18 AAC 30.520 - Inlets and outlets(a) Inlets for fresh or repurified water must be placed to allow uniform circulation of water and maintain a uniform disinfectant residual throughout the pool. Inlets must be submerged at least 18 inches below the water surface to reduce the escape of chlorine or other disinfectants. Pools installed after 12/23/93 must be tested by the operator with a crystal violet water distribution test or its equivalent to determine and adjust the recirculation pattern. This test must be conducted in the presence of a department representative, and must be approved by the department.(b) Anti-vortex main drains must be used in the deepest part of the pool and must be covered with grates that cannot be easily broken or removed by bathers. The maximum velocity of water passing through the drain may not exceed 1.25 ft/sec at 100 percent of the design flow rate.(c) If the pool is more than 30 feet wide, multiple main drain outlets must be provided. These outlets must be spaced not more than 20 feet apart, nor more than six feet from the side walls of the pool.(d) Fill and draw pools are prohibited. Flow-through pools will, in the department's discretion, be allowed, if a waiver of provisions is granted under 18 AAC 30.955.Eff. 6/4/83, Register 86; am 12/23/93, Register 128