6lb weight fluctuation

Hi everyone. I’m new here and new to water fasting. Today is day 6 and I’ve noticed that my weight fluctuates 6 lbs. I am only consuming water. For instance by day 3 I had lost 10 lbs but then put 6lbs back on the next day. Ever since then my weight has stuck at 211lbs. This morning it dropped to 205 but then went back up again. Could it be 6 lbs of water? And why isn’t the scale moving more?? Thank you to everyone for your help! Tweet