Here’s a recipe for making your own hydraulic lime on the cheap. Ever wanted to use hydraulic lime but not been able to find it in your area? Or perhaps you can find it, but it is going to cost you more than the rest of the house combined to ship it to your location. Have hope, there is a way to produce your own hydraulic lime from a much cheaper and more readily available source: quick lime and brick dust.
Simply add up to 5% brick dust to your quick lime and voila, you have a lime with similar properties to hydraulic lime. To be clear, it is not hydraulic lime, per se, but it behaves in much the same ways. This is considerably cheaper and the ingredients are available in most areas.