The acidified copper sulfate may be used alone in the water 1/4 tsp per gallon of water for 3 days per month to help prevent the spread of canker, a protozoan disease carried by pigeons.
If using the plain copper sulfate (not acidified) it has to have some acid added, such as citric acid or I suppose, ACV.
If using the plain copper sulfate (not acidified) it has to have some acid added, such as citric acid or I suppose, ACV.