How to Clean a Concrete Bird Bath to Remove Algae and Keep Backyard Birds Safe

Give your bird bath a good scrub every few days.

A bird perched on the edge of a birdbath in a garden setting — Credit:
WilliamSherman / Getty Images

A clean concrete bird bath not only enhances your garden's charm but also supports the health of backyard birds.
Regular cleaning every two to three days prevents algae buildup, keeps water fresh, and protects birds from diseases.
Avoid harsh cleaners like soap or ammonia—use mild solutions, scrub thoroughly, and rinse well to ensure bird safety.

A concrete bird bath nestled between plants creates a beautiful, English-cottage garden aesthetic. Plus, it provides a vital water source for backyard avians, which they use to hydrate, keep clean, cool off, and battle insects or parasites in their feathers.

"Bird baths can be a great way to offer water, especially in hot weather or during droughts," says Sarah Manning, conservation coordinator for Birds Georgia. "The three essential elements of a bird bath are cleanliness, depth, and safety."

While concrete is a popular bird bath material, it is prone to algae buildup, and without proper cleaning, it can spread diseases to your backyard birds. Proper cleaning (without leaving toxic chemicals behind) is essential for the health of local birds. Ahead, our experts break down how to clean a concrete bird bath, products to avoid, and how to keep it sparkling for longer.

Sarah Manning, conservation coordinator for Birds Georgia
Alicia Adamson, owner of Rustic Strength , a toxin-free cleaning products company
Sara Aparacio, cleaning expert with Homeaglow

How to Clean a Concrete Bird Bath

A concrete bird bath needs extra attention, since it's porous. Manning recommends cleaning it every two to three days, especially if you have a few or more bird visitors. She suggests utilizing either of two cleaning solutions:

Bleach solution: One part bleach/nine parts water
Vinegar solution: One part vinegar/nine parts water

While bleach and vinegar are effective cleaning products, Manning says to never mix them or use both at once. Combining bleach and vinegar results in the formation of chlorine gas, which is dangerous to breathe in.

Step-by-Step Cleaning Instructions

Once you've chosen your cleaning solution, follow these steps to thoroughly sanitize your concrete bird bath.

Dump the old water from the bird bath.
Remove any debris, like leaves or grit.
Rinse with a strong spray of water from a hose or pressure washer.
Mix your cleaning solution of choice.
Scrub the bird bath with a bristled brush.
Let the solution sit for 15 to 20 minutes.
Repeat scrubbing until all debris is gone.
Rinse the bird bath, dump it, and rinse it again. Repeat until the concrete no longer feels slippery.
Allow the bird bath to dry completely before refilling.

Why Regular Cleaning Is Important

Bacterial diseases like conjunctivitis and avian pox can spread through saliva and bird droppings, warns Manning. Keeping your bird bath clean helps prevent the spread of diseases among wild birds.

From a homeowner's perspective, stagnant water in a neglected bird bath creates the perfect environment for algae, bacteria, and even mosquitoes, cautions Sara Aparacio, a cleaning expert with Homeaglow.

Best Method for Removing Algae Buildup

The tricky thing about concrete is that it can look clean, even if it isn't. Alicia Adamson, owner of Rustic Strength, says she pays special attention to how the basin feels. "If it feels slick when you run your hand over it, that is the first sign buildup has started," she says. "Since concrete has texture, that film can grip the surface instead of rinsing right off."

To remove algae buildup, you need friction. She says to spray the bird bath with a solution of warm water and vinegar to loosen the algae. "But the brush is doing the real work. Scrub with a stiff nylon brush, rinse well, then check the surface with your hand," she says.

Products to Avoid

Skip soap, detergent, and most harsh cleaners, such as ammonia, disinfectant wipes, and undiluted bleach, when tending to your bird bath. "The main concern is residue, as birds put their beaks and feathers directly into that water," she says. "Use the mildest thing that gets the job done, scrub well, and rinse until you are confident nothing is left behind."

Tips for Keeping a Bird Bath Clean

To keep your bird bath clean for longer, take a look at its surroundings. "If it is under a feeder, a berry tree, or anything messy, you are making the water dirty faster," says Adamson. Consider moving it to a location where debris won't land in the bowl.

Also, never let the bird bath water sit for multiple days in a row. "Dump and refill it every three days if you can," says Adamson. This will help keep the water fresh and prevent algae buildup.