For the last few months, we've experienced long spells of drought and heat in Massachusetts, on the East Coast of the United States. At least thirty birds and three generations of squirrels and chipmunks are drinking and bathing here at any given time, and they're not alone. At night, we've seen raccoons climb clumsily up the birdbaths and knock them over.

We have a number of different water vessels. Keeping them filled is very important to us, but we don't always have time to thoroughly clean out the dirt, old food, and bird droppings. Not surprisingly, algae is more prevalent this year than usual, especially in the cement baths, where it hides in crevices. We really don't like that slime, and generally scrape it off with a wire brush, but it is time-consuming and we're probably not doing it as frequently as we should. We could stop using the cement and stone vessels, but many of those we're feeding prefer them over all others, so that's not our first choice.

Depriving the animals of water seems dangerous, even for a few hours on an intermittent basis. However, we're concerned that after having what looks like a refreshing drink and bath, they go off and become ill or die due to negligence on our part.

Is anyone aware of a consensus as to whether or not dirty birdbath water is worse than none at all?

  • 2
    I've just blasted my stone birdbath with water from the hose and refilled it, thanks to your question.
    – ab2
    Aug 12, 2016 at 0:03
  • 6
    Can it be any worse than the small puddles, scummy ponds, and almost dried up bits of water they find on their own anyway? I doubt it very much. Birds thrived for millions of years before anyone thought of providing water for them and they'll do just fine if you never bother to clean that birdbath again. Aug 12, 2016 at 3:44
  • 2
    @Carey Gregory: precisely this. What seems "dirty" or "unhygienic" to us today, is often natural and normal in nature - or even in human society just a few generations back. We are so obsessed with cleanliness (even if only superficially) that it's started to become unnatural, and in some cases can be actively harmful to nature, when considering not only chemical cleaners, but also the removal of certain bacteria or insects that are part of the natural balance. Nature gave many animals robust organs (such as how dogs have filters on their tongues) for a reason.
    – flith
    Aug 13, 2016 at 15:19

1 Answer 1


I guess dirty water is better than no water. I don't think algae will kill them. The primary danger is parasites.

Concrete cleaner is the easiest way to remove algae but be sure to rinse thoroughly.

You can also get animal safe algaecide.

I use a 5 gallon paint bucket for my dogs. In the summer by the time they finish it will have a little bit of algae. I clean with a bottle brush and dish washing liquid. Then a splash of bleach. It cleans really fast. Not pretty but maybe put one out of view for the raccoons. In the shade - algae and other plants need sun light.

  • You are not going to drown chipmunk. A chipmunk can find it's way out or a 5 gallon bucket.
    – paparazzo
    Aug 15, 2016 at 0:27
  • You are more likely to make them sick with soap, bleach. algaecide , etc. than the natural water and mud they have been living with for millions of years. Feb 1, 2018 at 1:30
  • If it's concrete and pretty solid you can also pressure wash with just water.
    – Aravona
    Sep 24, 2019 at 7:55

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