The reason I asked is because high pH + high TA + high calcium hardness can = cloudy water. (Otherwise, you are right, CH is not an issue in a vinyl pool.) Have you been using cal-hypo for awhile? Maybe run that test again and let your wife read the results of it.

Was your pool green when you opened it this spring?

See if you can find a small bag of DE. Throw a handful into the skimmer while your pump is running and watch the return jets. If you see white powder shooting back out, your filter is not working properly. If it doesn't shoot out, then the DE may actually help your filter work a little better. More about that here: http://pool9.net/de-test/