During photosynthesis, the overall reaction can be summarized as:
\[ 6 , \text{CO}_2 + 6 , \text{H}_2\text{O} \rightarrow \text{C}6\text{H}{12}\text{O}_6 + 6 , \text{O}_2 \]
From this equation, we can see that when one molecule of glucose (\(\text{C}6\text{H}{12}\text{O}_6\)) is produced, 6 molecules of water (\(\text{H}_2\text{O}\)) are consumed. Therefore, the number of water molecules recycled (or used) when one molecule of glucose is created is 6.