At what level does your catchment have to be....

[Beachboy]

I went back out to my garage to check out pressure gauge & tank. Written on tank it says 75 psi. So is that where pressure gauge should be, or is that "the max", for this size tank? Oh yeah, pressure gauge is just below 40psi too. Is that a normal level, or what?

I'd also like to take this time to thank you all for your responses too. Now if only I could understand what all you are telling me??