I'm in the same mindset as the other two up there. I've only had to really monitor my sorority in the beginning; it has since been fairly established and it's been absolutely fine. I have to leave it during the school season because I'm up at college and can only come home on the weekends to do tank maintenance (my mom flat out said she wouldn't be doing anything but feed my fish, not that I mind because she has never cared for an aquarium and my stepdad has mentioned things like bleaching the accessories to get some of the water stains off, so I don't want them touching the water anyway). I'd take them up with me, but it's a 29g tank so there's no room AT ALL in the dorms xD So I just take my two 5 gallons with my boys instead.
But yeah. I left my girls for five days weekly without a problem, and it has occasionally gone up to two weeks during occasions I got extremely busy with school work and just could not make it down, and the girls were absolutely fine.