I have a beautiful concrete birdbath which is constantley in use.
Unfortunately after about four days it has gone green and it takes a lot of scrubbing
to get it clean again.
CouldI paint it with anything that might cure this problem without harming the birds?
I’m not sure that painting would be a solution, but I believe that charcoal, (barbecue charcoal?) will help keep the water fresh. Also, is it movable out of direct sun?
It will stay cleaner longer if you scAld it with boiling water after getting it spotless. The trick is killing the algae spores a second bird drinking area is a good idea. A plastic plant saucer is popular especially if you put a few pebbles in the bottom
/// the wood pigeons tend to use it as a toilet.///
I have that problem too, and as a result I replace the water every day, giving the bath a brief scrub at the same time.
In this current hot weather I too have introduced a second bath (a shallow plant tray), much to the apparent delight of a blackbird I watched splashing away this afternoon.