Here is my spreadsheet that I have used to make a version of soylent.
It seems to work nutrition wise, but it doesn’t taste very good. If anyone has any input on improving the taste that would be much appreciated. I tried not adding the fish oil, that helped a small bit. My whey is unflavored, so I have been adding vanilla, this helps a fair amount. I might try adding cocoa powder instead of the vanilla at some point.
Edit: I don’t recommend softgels even though I have them on my list. They don’t dissolve over night, so you have no choice but to use a blender if you use them. And you don’t have as much control over dosage.
Edit 2: Here are some rough directions for my ingredients, I wouldn’t follow these without double checking each thing for the amount that you want. For any item that you don’t get exactly what I bought this won’t be of use. The small measurements of things like “drop” and “smidgen” are from the measuring spoon set in the amazon link and are a guide for weighing.