Messed up Guild! HELP!

[problem] : when i invite someone to my guild, they get invited to a high rank such as officer.

i am currently running a guild, something am not very familiar with.
my guild consists of 8 ranks, were the initial guild ranks are 5. 3 extra ranks for alts, such as officer alt, GM alt, and alt.
now does anyone know exactly what the default invite rank is? is it fixed to rank 5? how to change that if you have 8 ranks?

below is the rankings in order.

rank 1: GM
rank 2: GM alt
rank 3: officer
rank 4: sergeant
rank 5: officer alt
rank 6: grunt
rank 7: recruit
rank 8: alt