Get Rid Of Algae And Prevent It From Coming Back With Two Simple Ingredients

Algae can show up in all the wrong places: pools, patios, decks, roof shingles, rain barrels, fish tanks, birdbaths, and steps. If left unchecked, algae can be more than a nuisance — it can be a health hazard, especially for people with respiratory problems. But there's a simple solution to unwanted algae growth: water and vinegar. 

The acetic acid in vinegar works to break down algae. While undiluted vinegar can be toxic, a properly diluted solution is biodegradable and non-toxic, yet it still provides enough acetic acid to remove algae without harming plants, fish, birds, or other wildlife. A good recipe to start with is a 10% solution made from nine parts water to one part vinegar in a spray bottle or bucket. For larger areas, an even weaker 5% solution may be sufficient to kill algae, while you might use a stronger solution of up to 30% to clean vinyl siding with vinegar. Apply the solution to surfaces affected by algae, scrub the surface with a bristle brush until the algae is removed, and then rinse with water. For significant algae buildup, wait 15 minutes or more to allow the solution to sink in and penetrate the algae. If the algae buildup is significant, you may want to use a power washer.

Standing water or regular dampness creates a perfect host environment for algae growth, especially if it is in the shade, so the first step to keep algae from returning is to give the area as much water circulation as you can. For instance, if you have a pool, make sure the filter is running regularly, or add a fountain to a bird bath to keep the water moving. Additionally, keep your gutters clean so that the water empties out rather than accumulating, and create better drainage around walkways, patios, and other low areas. In an enclosed space, you can use a dehumidifier to prevent dampness. 

Sunshine and fresh air are also great deterrents to algae buildup, as they help keep otherwise moist areas dry. However, if you're trying to remove and prevent algae in a fountain or other movable fixture, move the fountain into the shade, as algae will use the sunlight to photosynthesize and grow. To prevent algae from growing in standing water, cut back tree limbs that shade an area where algae sometimes accumulates. 

Keeping walkways and patios clear of debris that can trap moisture will inhibit algae growth on these surfaces. Regular cleaning helps as well — just fill your hose-end sprayer attachment with a 5% to 10% vinegar solution and hose down shady areas of your walkway, roof, siding, patio, or deck. Ran out of vinegar and don't want to rush to the store? Check out another homemade cleaner for outdoor algae.