So I have a problem that really isn't a problem. At my school, I have 3 professors that I know very well and have done research with. They all could write me very glowing and personal recommendations, but I go to a liberal arts school and I'm applying to school for Geophysics. Right now I'm doing an REU in Geophysics at probably the top program in the united states, give or take a few schools, and while my adviser thinks i'm doing great work, he has only known me for a few months and I'm not sure how personal his recommendation will be. My GPA is low for applying to pHD programs, but I was told I got into this program(REU) because of my glowing recommendations and research experience, so I am wondering if I should just stick with all the professors at my school or boot one out for my adviser. Any thoughts?