Expect more questions.
I am presuming you have an inground sprinkler system. Is that correct? I am confused by the mention of garden hoses.
My sprinkler system is having a similar issue that you are reporting. My back yard is just under a 1000 sq ft. It was originally designed to have one zone. My water pressure coming out of the back yard hose bibb is 80 PSI. I never figured out the flow rate but it was assumed to be sufficient based on the PSI.
The system was designed so that 1 leg ran down the one side of the yard, and the other ran down the back side of the yard wit a couple of heads in the center. The system was designed to account for possible low flow rate so it was set up as a single zone. The sprinkler heads were mostly Rainbird and were
The guy who designed it also installed it. And he had help from another experienced designer/installer. They used 1/2" flex pipe between the heads to allow for ground movement as I live in the Rocky Mountains. I have 1/2" ID copper running to the hose bib which was a freeze proof type.
When they tested the unit, it didn't work at all. So, they split it into two zones. The front zone worked well with minor adjustments. However, the back zone still didn't work as it may have had too many heads. One of the heads was tightened down so that it was taken out of commission. The others were adjusted as well until the back one started working. I used a garden hose connected to timer that controlled multiple zones. I used it to control the two zones. It worked okay but there was still some flow problems.
Next year, I still had some flow problems so I decided to do what I could to remove any restrictions from the inside of the house, I put in 3/4" PEX from the trunk to the a ball valve where I transition to 3/4" copper to pass through the exterior hole, where I put in another ball valve and switched back to 3/4" PEX. The PEX ran to a junction where it split into two 3/4" zone valves. From there it transitioned into the pipe used by the sprinklers. That helped quite a bit. Enough that I wanted to open up the closed down sprinkler head. (I am still trying to find the damn thing!!)
I went through my system to give you a breakdown of what was used.
So, some questions for you:
Do you have an inground sprinkler system?
What size pipe is feeding the connection where you are connecting the sprinklers?
Are you using a hose bibb to connect to the sprinklers?
Are you using a garden hose to supply water to the sprinklers?
If so, what is the size and length of the garden hose? (NOT the size of the connector!)
Is the pipe connecting the sprinklers solid or flexible?
What size is the pipe?
How is the water supplied to the pipe feeding the sprinklers?
