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This colon should be replaced with a semicolon.

Colon can be used between two main clauses in cases where the second clause explains or follows from the first. http://www.oxforddictionaries.com/words/colon

The main task of the semicolon is to mark a break that is stronger than a comma but not as final as a full stop. It’s used between two main clauses that balance each other and are too closely linked to be made into separate sentences. http://www.oxforddictionaries.com/words/semicolon