Chemistry

Hey guys, i have a question about how to figure out how much mass of a compound i need to find 130ppm here is the question.

What mass of Fe(NH4)2(SO4)2*6H2O is required to prepare 2.25 L of a 130 ppm iron solution?

Now i know that ppm is (mg of desired compound)/(kg of solvent used) But in this case im not quite sure what the solvent would be?

Would the solvent be the previously explained Fe..... compound just minus the Fe? or would the compound just bethe 6H2O? im confused, if anyone could help that would be great.