Hello:

How can i , for the same product, put different tax values for each attribute.

I explain:
The product is a fertilizer for plants, that product comes in bottles of 1, 5 and 10 lt.
The bottle of 1 lt. has a 16% tax value , while the 5 and 10 lt has a 7% tax value.
Now, how can i put different taxes to the attributes if the tax value i have to give to the product?

I really don't want to make different products.

SOMEBODY HELP ME?