How much tuition you can carry forward depends on how much you need this year to reduce your tax owing. For example, if you have $10,000 in tuition and your tax situation is such that you need $1000 to reduce your tax owing to zero, you'll carry forward the remainder of $9000.

CRA requires that any tuition amounts be used when possible. There's no option to save these amounts. So in the example above, you must use that $1000. You cannot choose to use only $500 and save the rest. The amount of tuition applied is done automatically by TurboTax so you don't have to worry about the calculation.