Just recently moved into a house that has a well system for irrigation. The pressure tanks was leaking so I went and got a new one. Flotec 82 Gal 20/40. Also replaced the power switch (broken)pressure switch (DSquare 20/40)(rusted) and control box. Initially, system was working until pressure tank finally stopped holding air. This is why I replaced all the old parts. I have tested the power (good),pressure in new tank was dropped down to 18 psi. When I go to start sprinklers...they don't come on. Pressure gauge near pressure switch reads -0-. Pump is 3 wire submersible, believe 1hp (thats what was written on old control box).

Am I forgetting something?