How much copper sulfate to add for container citrus?

[Tropicaltoba]

Hello all, last year forum members help me out a bunch by identifying copper deficiency in some of my containerized citrus. It appears to be a seasonal issue probably related to cool container temps with a high organic content. Copper sulfate should fix the problem, but it is typically applied as a fungicide spray. Issue is I don’t want to stain the walls/floor of my gh, so I need to add it to the soil. Does anyone know how much to add to container plants?

[Millet]

I don't know the exact recommended amounts for in soil applications.  However, I know that copper is required by citrus in low concentrations (5 to 16 ppm.).  When applied directly into container mediums it is becomes bond tightly in organic matter and can be deficient in highly organic soils.  It is not lost from soil, but it may be unavailable.  The better method would be by spray.