Yes, Lil, it's very possible to swing that much during TOM (and not during TOM for that fact). Fat cells don't just hold fat, they hold water, and when your hormonal balance changes those cells can grab on to more water. The more you weigh, the bigger the swing will be, relatively speaking. When I first started I would see a change of up to 8-9 lbs, and now it's more like 2-3.

Whichever technique causes you the least stress is the better one. If you can handle the daily fluctuations then stick with daily - if not, go with weekly, heck go with monthly

-N