I buy grit from the feedstore. I think it is called GraniteGrit or something like that. It is various sizes, the larges surprisingly big, like a chopped-in0half pencil eraser. The girls must eat it because I do refill the tin every few weeks.
Regarding sand, if it's the stuff folk use for sanding roads in the winter, make sure you know what's in it. I asked our town for some when we were building the run, thought it'd be a good "floor".... and they said "sure BUT be aware it has salt mixed in to aid de-icing the streets"..... needless to say I didn't take any, as it would probably have been bad for the birds.
Regarding sand, if it's the stuff folk use for sanding roads in the winter, make sure you know what's in it. I asked our town for some when we were building the run, thought it'd be a good "floor".... and they said "sure BUT be aware it has salt mixed in to aid de-icing the streets"..... needless to say I didn't take any, as it would probably have been bad for the birds.