Limestone Flour - quantity?

[Moomin1]

Does anyone know how much limestone flour should be given in feed/what dosage (for want of a better word) per kg horse?

I have a bag of the stuff but it has no instructions on and never used it before!

 

[Jnhuk]

introduce gradually 20 to 50g is the range depending on size of your pony/horse but general average is 40g per day

 

[Moomin1]

introduce gradually 20 to 50g is the range depending on size of your pony/horse but general average is 40g per day

Thanks