How do I clear up the water that has built up inside my air hose?

The best way is to use a blow tip. This is a tool that is normally used with air hoses to blow dust off tools and equipment; it offers a free flow of air when the trigger is actuated. To clear water, make sure the compressor is at a higher position than the hose by putting it up on saw horses or workbench. The hoses should be uncoiled; and if possible, run them downhill so that the blow tip attached to the end of the hose is at the lowest point. With the compressor plugged in, turn the switch on and be sure that it pumps up to maximum pressure. Leave the compressor switch on and open the blow tip by pulling the trigger and allow air to simply free flow through. Be sure that the blow tip is pointed away from anyone in the area and also away from any object that you do not want to stain. If there is a lot of water, it can spray excessively in the initial flow of air, and any sand, rust, or oil particles that are in the shose will come out with it. Continue the air flow until you are satisfied that all of the excess moisture is out of the hose. This procedure is especially important in colder conditions if the hose is to be stored outdoors or in cold conditions when not in use; pooling water will freeze solid, causing long delays in morning startups.