Sweep your patio with a broom or run a leaf blower over it to remove debris.
Fill a bucket with a mild cleaner. Dip a mop into the bucket and wash the concrete. Work from one end to the other until the surface is clean. Let dry.
Get a fast-drying clear sealer. Use an acrylic-based one for cost-effectiveness and ease of use. The sealer forms a thin layer of protection and resists UV penetration.
Fill a bucket with the sealer. Tighten all connections of the pump-up sprayer.
Pump the sprayer tank and wave the wand over the concrete, depressing the trigger so a light mist shoots out. Lock the trigger down if your wand has that option.
Pump the sealant out as you move the wand over the floor, covering all of the concrete with a thin coat. If you are sealing a large area, start at one end and walk backward to the other side so you cover the entire floor.
Wait for the first layer to dry. It usually takes 2 to 4 hours.
Mist a second coat of sealer onto the floor. Let it dry. Apply a third coat if desired.
Apply a new coat of sealant every year or two to maintain the stain.