Abstract: An apparatus for mixing photographic process chemicals, and supplying the mixed chemical to a film processing unit. The apparatus provides a chemical holding tank having a water supply inlet and a chemical discharge outlet thereon. The tank is provided with submersible pumps for agitating the contained chemical. Sensors on the inner portion of the tank detect when the process chemical reaches a minimal level whereupon water is added through the water inlet to fill the tank to its maximum whereupon the water supply is automatically shut off. In the preferred embodiment, an operation can add dry chemicals or liquid concentrate to form the finished process chemical. The sensors can be adjusted to vary water levels as needed for adapting the system to different chemical-water mix ratios as specified with the concentrated chemicals supplied by different manufactures.