lawn sprinkler pump

I have low water pressure. I spray liquid fertilizer and chemicals with a hose end sprayer and the spray only goes out about 3-4 feet. It goes about 20 ft. when I use a RainBird knocker. I'd like to know if I bought a lawn sprinkler pump about 3/4 hp up to 1 hp and put a hose on the end of it and hooked up a RainBird knocker to the other end, with the low pressure I have, would I be in danger of the pump pulling more water than the faucet can furnish. If I would be in danger of pulling more water than the faucet can furnish the pump, could I first feed the water into a 50-gal. barrel so I'd alway have a supply of water and pump the water from the barrel. I've been told to use a smaller diameter hose. I use 3/4 now. Would 5/8 make that much difference. Or do you have some other solution to my problem.

Yes, the smaller diameter hose will make a difference. It will increase the pressure in the line.

Hi,
Just wondering, why do you have such low water pressure? Is it city water or a well?
Is it low for a purpose?
Keiser ...