Sometimes, you might feel that to be on the safe side, adding a little implicit wait in addition to the explicit wait will help. Never do this! This can have unpredictable results. Doing this may increase waiting time, or may give you an ElementNotFoundException.
Decide on a particular wait and use that throughout; this is the best strategy to apply.
Using a combination of implicit and explicit waits will make your explicit waits break and produce unpredictable results.