Amniotic fluid questoons

Stacy • Finally after 4.5 years, I'm pregnant! due November 29, 2016 with a little girl!!!!
What is your amniotic fluid supposed to be at in inches around 24 weeks and a few days? My doctor told me to drink like a fish because my fluid is at 10cm but it's not considered "low" unless it's at 5cm? I'm so confused