How to Remove Water Stains From Stained Concrete

Water stains come in three varieties. There are pink or reddish stains caused by the iron in the water, dark stains caused by algae, and white stains from the minerals in the water. On most concrete surfaces the stains can be removed with a power washer. But if your concrete walkways or patio is a stained concrete, the power washer will remove the color. The stains don't have to be permanent though, as there are ways to remove water stains from stained concrete.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• Water
• Bucket
• Gloves
• Oxalic acid
• Oxygenated bleach
• Scrub brush

1. Study the stains to verify if they are rust, algae, or mineral water stains. If the stains are caused by rust you will need to purchase oxalic acid, which is available from home improvement and hardware stores. For algae and mineral stains you will need to purchase oxygenated bleach. Do not use chlorine bleach as it will kill any nearby plants.

2. Mix 1 part oxygenated bleach to 2 parts water. If cleaning rust, put on rubber gloves and follow the manufacturer's instructions to mix the oxalic acid. Oxygenated bleach is non-toxic, but oxalic acid should not come in contact with any bare skin.

3. Dip the scrub brush into the cleaning solution and scrub the area thoroughly until the stains are gone. You may need to scrub an area more than once to get rid of the entire water stain. For a large area, use a deck brush instead of a hand held brush.

4. Rinse the cleaning solution from the concrete with clear water. If you used oxalic acid keep children and pets from the area for at least 24 hours.

Tips & Warnings

• Keep concrete sealed so that water stains do not penetrate deeply.
• Only use oxalic acid in well-ventilated areas.

Resources

• Concrete Network provides information on many different commercial concrete cleaners and methods.