axsquareplusbxplusc

just want to ask why is the "Ranger" argricaultrial modual transfer rate so low?, it is only 1.25% load I am currently landed on kerbin for testing and there are at least one 5 star scientist onboard, with 68000 fertilizer, 7200 supply and enough electricity not only this modual but also the 3.75m cylinder type argricultrial modual also encounter the same problem