I am doing the cooler within the cooler technique for a freezer in my 150 qt cooler....I have a Styrofoam cooler that takes up about one third maybe more of my cooler... I'm launching on a main salmon and it should he pushing 90 to 100 for the next week... I have never bought dry ice before... how much do I need??? Packing techniques? ??? I launch on monday have to buy dry ice tomorrow. ... any info helps...