First off, how deep the pool is has nothing to do with deck joist sizing. Second, you don't really have a 16' bye 14' deck. Depending on how you frame it, your longest span might be 16'....or it might be 14'....with a bunch of shorter spans in the thing. That said, if you had any thought of spanning either 16' or 14' with two bye sixes, think again. No way. Ron