From the MS website:
Pool Closure in Early 2017
The Sandcastle Pool at Disney's Old Key West Resort will be closed for refurbishment from early January 2017 through early March 2017. The leisure pools located at Old Turtle Pond, South Point and Miller's Road will remain available for your enjoyment. Please check back here for updates.
Thank you, that's a bummer. The email I got from Disney last week "regarding our stay" said it would be "from early January 2017 through 2/24/2017".It doesn't look like it will be open this month.