The question is not how much SH to put into the house wash solution but, how much house wash solution do you need to make up. Then everything else is percentages based upon what a normal 100 gallon mix uses of each solution.
If you have a 50 gallon tank that has 50 gallons of water and one gallon of Emulisier Plus it is going to overflow. That is 51 gallons in a 50 gallon tank. Go figure.