Acid soil has a low pH, Kevin. You might want to lower the pH of the water you're using on those plants by adding a splash or two of vinegar (about a spoonful per gallon) to it. Neutral pH is 7, below that is acidic and above that is basic. You can test your water with an aquarium test kit if you want to know an exact amount of vinegar to add.
But as I said before, the soil isn't particularly critical to pineapples because the roots are mainly anchors, not feeders. Concentrate on feeding your pineapples by spraying the leaves. In Hawaii they grow fields of pineapples on rocky volcanic soil, and here in Florida there used to be a huge pineapple industry with the plants growing on our alkaline grey beach sand-y soil.
Yes, lots of people use "willow water" or willow tea as a rooting compound. You don't really need to grind up the branches, just take a thin branch and cut it up in little pieces with a scissors, then 'brew' it in water for a few days in the sun, like tea. The rooting hormone is in the bark and it suffuses into the water.
When I root pineapples, I just take the top and stick it straight into the soil, then keep the leaves misted for a week or two. (I have a misting setup for my orchids so they just sit out there)
This is one that I grew from a top. It takes two years to grow a fruit, then the mama plant makes pups (new plants) for you, and dies.
