Hi NoviceDIY, the only way to adjust the water flow strength would be to increase the pressure of the system. For example: If you're using a rain barrel or gravity fed system, this means your water tank would need to be installed at a higher height. Another way to increase the pressure in your irrigation system would be to install a regulator that regulates the pressure to a higher pressure, for example if you're using a 25psi pressure regulator, try installing a 30psi or 35psi pressure regulator to increase the water flow strength.