Abstract: This mixing apparatus is for use in incorporating a base material, such as powder, into a liquid carrier material. The mixing apparatus includes a venturi mixing device used in conjunction with a pump which delivers liquid from a container to said device, to draw the powder from another container by venturi action.The mixing device includes a T-shaped fitting receiving an intake insert for the liquid and an intake insert for the powder into two of its branches, and receiving a discharge insert in the remaining branch. The liquid insert and discharge insert are spaced apart to create a venturi throat inducing powder to flow through the base material insert and through the discharge insert which is configurated to facilitate mixing. The base material insert is removable for replacement with another insert to suit a different base material.