will keeping pool covered during the day with filter running cause algae? How often should I cover it?

Answer 1

Keeping the filter running for a min of 8hrs a day and adding an algaecide will help tremendously. Usually once a week depending on what brand you use. Follow directions.
Make sure you check all levels of chemicals in check.
You don't need to cover your pool.
Make sure you backwash your filter at least once a week.