If you kids are anything like mine they need new things to entertain them.
Something I love to do is get some food coloring and put a few cap fulls into the bath and then get some bath toys to make it into a theme.
My boy loves to make it into a green swamp with his dinosaurs Or make it as blue as the Sea and get some ocean creatures.
My daughter loves to have it pink and gets her Barbies in there for a pool party. This is simple and cheap gets there imaginations going.