like Rage said...its not possible to....create 2 containers and mix them together...thats not possible !
well u can create more than two emitter in a container and have an effect of mixing...it up..if u want to ..mixxing
......yeah....offcourse. well there is update of fluid preset get ur one from aliaswavefront community site......it have that more than two emitter example ...... it might help...........