There are a few key differences between liquid and granular humic acid that may make one or the other a better choice for your needs. Liquid humic acid is more readily available for plants to use, but it can be leached out of the soil more easily. Granular humic acid takes longer to break down and become available to plants, but it will last longer in the soil. So if you need a quick boost of nutrients for your plants, liquid humic acid may be the way to go. But if you want something that will continue to nourish your plants over a longer period of time, granular humic acid may be a better option.