Air in tank | Terry Love Plumbing Advice & Remodel DIY & Professional Forum

So i bought a drummond shallow well pump and 5 gal tank. The directions say the tanks bladder has been pressurized to 23 psi.
Can i safley add air to make it 28 psi or is 23 psi the limit.
Like most directions now a days they are really vague and dont tell you much.

Thank you.