"I have been working in a variety of agricultural fields; plantations, nurseries, flower production, vegetables and herbs. There are always the same dilemmas when trying to calculate the fertilizer mix to use: Which fertilizers can be mixed together? How much fertilizer can be safely dissolved in a tank without danger of solidification or chemical reactions? What can I use as substitute when one of my regular fertilizers isn't available on the market? Which mixture will be the least costly? How do I use my water and soil test results in recalculating the amount of nutrients required? How can I know exactly what concentration of each nutrient is achieved with each recommended recipe? I used to search in books and browse the web for solutions for all these. Some answers came from books and went into Excel charts I made, and some could be calculated on various on-line web sites. But not all my questions could be answered, and whenever I changed one ingredient, I had to go back and recalculate everything. SMART! gave me the perfect solution. Any question or dilemma is very quickly resolved and nice clear printouts are ready for the irrigation team in seconds."