the thing about home made is that the pH down solution you make will actually only work temporarily , that's my experience with vinegar and lemon juice, your best bet therefore is to assure a well balanced "soil matrix" meaning make sure you've got all the right bacteria at work so your soil buffers all on it's own. so try looking for organic humic acid (will regulate the soil to 6.5) add beneficial bacteria like Bacilus Subtilis and myco, or simply try apple cider vinegar for pH down and aloe for pH up