Algae in the birdbath?

Stale water and warm weather are not a good combination, so if there’s slime and algae present, here’s what to do. About once a week, bale out the water with an empty yogurt carton and, with a solution of equal parts clear vinegar and warm water and using an old toothbrush, give the birdbath a good scrub and rinse well with fresh water. The birds will love you for it.