Do I need to soak or flush the bottle filter before using it?
When you open a new bottle filter, you should soak it for about 30 minutes prior to use. That will rinse any residual carbon out of the filter and help it to pass water more smoothly. There's no need to flush the bottle filter. You can screw the blue filter into the blue wing nut at the bottom of the straw once it's done soaking and you’re good to go.