To achieve small changes in GPM rate, which should you adjust?

Adjusting the pressure regulator is the most effective way to achieve small changes in gallons per minute (GPM) rate. The pressure regulator controls the flow of water in a system by maintaining a consistent pressure, which directly influences the GPM output. When the pressure is decreased, the flow rate will also decrease, allowing for fine-tuning of application rates.

On the other hand, while nozzles can also affect flow, they are generally used for specific application patterns or droplet sizes rather than for making precise adjustments to GPM. Changing tank size does not directly impact flow rate; it affects overall volume but not the rate of flow. A flow meter is designed to measure the GPM but does not control or adjust the flow itself. Thus, for making small adjustments in the water flow rate, focusing on the pressure regulator is the best approach.