I'm confused on this one...

Do you put a check valve between the pump and tank or not?

The instructions that came with my pump said to install them every 150 feet or so (can't remember exactly). Yet other instructions and web sites that I read say NOT to put any inline?

Who's right or wrong and why?

I realize the pump has a check/flapper valve at its head, but wouldn't a check valve at the tank help?

Would you want the drop line holding full pressure?