Hi, Silverette -- Mostly we don't say much about lye and water, because those depend on the preference of each soaper -- what superfat and what lye concentration each person likes best. I know some websites and books specify everything in the recipe, but that limits you to only what the book author or website owner thinks is best -- and that's not always a good idea. Even when everything is spelled out, it's a wise thing to always, always run the recipe through a
soap recipe calculator to make sure there is no typo or other mistake -- if you don't double check someone else's recipe, you run the risk making a batch of bad or unsafe soap.
If you have never used a recipe calc, then now may be a good time to consider learning. It's not hard to do once you've tried it a time or two and it will be a huge help in your soaping to be able to do these calculations. Here's a link to a tutorial for SoapCalc:
http://www.soapmakingforum.com/showthread.php?t=49627
To figure the lye and water for YOUR version of the 80-15-5 recipe, you would put the percentages of the fats into the calculator, choose a total weight for the fats, set the superfat to your desired amount (the default is usually 5%, but typical range is 3% to 8%), and choose your preferred lye concentration ("full water" is about 28%, but typical range is 28% to 33% lye concentration). Once all that is set, then let the calculator figure out the amount of lye and water.
As far as the soap you made looking chalky and falling apart -- we need to know the specific
weights of everything in your recipe and how you made the soap. Without good information, it's nearly impossible to give good advice. Also a picture would help to show exactly what you mean.