I try to grab weights the first week of a month the day before OR a few days after feeding day. This is kind of iffy because all my snakes under 500g get fed once every 5 days while my other snakes get fed once a week and my males at 1000g+ get fed once every 10 days so it is extremely dependent on when everyone has an empty belly. (Weighing a snake with a medium rat in it's belly kinda feels like cheating lol). But yea, people are very worried when snakes are not eating and growing. In this case it may have been a little more extreme with Rain having to be tube fed. But it really goes to show that depending on the snake, how it eats, its birth weight, and the list goes on that can effect a snakes size.