How much detergent should I use in the Whirlpool 8575985 dishwasher?

The amount of detergent depends on water hardness and soil level. For example, with soft water and light soil, use 4 tsp (20 mL) in the Main Wash section, while hard water with heavy soil requires filling the cup completely with up to 9 tsp (45 mL) in the Main Wash section. Tablet detergents must be placed in the Main Wash section with the cover closed, and you should follow package instructions for liquid or concentrated detergents. (Page 13)