conversely

/ˈkɑːnvɜːrsli/

con·verse·ly AW

BrE /ˈkɒnvɜːsli/

NAmE /ˈkɑːnvɜːrsli/

(formal)

in a way that is the opposite or reverse of sth

You can add the fluid to the powder, or, conversely, the powder to the fluid.