What should be done experimentally when using an equilibrium phosphate program?

When using an equilibrium phosphate program, it is essential to determine the correct amount of phosphate to maintain in solution. This is crucial for effective water treatment, as the right concentration of phosphate helps to inhibit scale formation and corrosion in systems such as boilers and cooling towers.

Maintaining the correct phosphate level ensures that the water remains in a balanced state, where it can effectively prevent deposits on metal surfaces without leading to excessive phosphate accumulation, which can be environmentally harmful and lead to other operational issues. The effectiveness of the program relies on managing these phosphate levels to ensure optimal performance and safety in the operational process.

Other options relate to aspects that might be involved in management or adjustments of phosphate within a system, but they do not address the fundamental need to establish the correct concentration of phosphate to achieve the intended equilibrium.