Ok, hopefully I can explain this clear enough to get some help. I have attached a drawing.

We recently upgraded our pressure tank and moved it from the barn to the home. The problem we were having was low pressure on the second floor of the home and since the pressure tank was so far down hill we thought it would help to move it. We put in a 125 gal pressure tank with the pressure set at 60/80.

The well makes about 10 gals per minute with a standard well pump.

What seems to be happening is that occasionally we will not have any water or very low pressure at the home. The pressure gauge on the tank will read may 10 lbs. I will go to the barn, where the pressure gauge is and the pressure will read about 30lbs with the pump running constantly. I will shut the pump off and drain water out of the system, which is very little, should be quite a bit as the entire line should be full of water. Turn the pump back on and everything is fine.

It seems like we may be getting a vapor lock up top somewhere. Maybe between the T and the pressure tank or ?

We did not have this problem before when the pressure tank was at the barn. So the obvious answer is move the tank back to the barn? But that doesn't solve the low pressure at the home.

So I was thinking of putting another small pressure tank at the barn and leaving it set around 50/70 lbs to try and even out the pressure from the bottom up or just a storage tank to take some of the volume out of the equation.

Hopefully someone with some experience can help with this equation.
Thank you for your input.