Your badder tank kicks on at 25 lbs what should be the air pressure in the tank?

The pressure in your tank should be checked with water drained from the tank, with the water drained the air pressure in the tank should be set 2psi lower than your kick in pressure. So for a kick in pressure of 25psi the tank air pressure should be set at 23psi.

Ans 2 - Water should NOT be totally drained from the tank or you may get a false reading ! - Leave 2-3 gallons in the tank. Most systems have the pressure switch set at 30 Psi, so tank residual pressure should be 28psi. - Lower than this gives really dismal pressure in the shower, especially if it's on second floor.