The filter is on a timer runs eight hrs at night, im wondering when thats done in the morning or when filter not in use am i suppose to close the inlet and outlet valves or can they just remain open.

And if they r to remain open when they get closed by my hubby on accident (filter was off) or when close them to change cartridge. When reopen to i need to open the valves on the filter and wait till water rus outs then reclose valves on filter to get any air out. Pretty sure do that when change cartridge but what about if they get closed any other time.