I moved into a new home in the country 8 months ago, so I'm learning about all sorts of house stuff that is new to me

When we moved in, we found the well pump was not sounding "smooth"; like maybe it was sucking air. As well, using the washing machine, or multiple taps, etc. at the same time caused the pressure guage to drop to zero. This pump is 3/4 hp. I found some very rough, old documentation, that indicates the well is 75 ft deep.

A few months ago, we called our local plumbing company, and they replaced the jet pump. On my request, they upgraded the pump to a 1 hp. Problem is, the pump still doesn't seem to be running properly. I think the upgrade to 1 hp is just masking the real problem. I think the original pump was fine.

Questions:

1.) Both the original pump, and the replacement, only have one pipe connected to them. From what I've read, this means they don't have a deep well injector, is this correct?

2.) Do my symptoms sound like I need a a deep well pump?

3.) There is actually a 3/4" pipe coming into the basement with the well pipe. Is it possible that this is in fact intended to be hooked up to a deep well pump? Could it be something else?

Thanks for any help anyone can provide.

--Chris Foran