Humic acids help to break up compacted soils, boost seed germination, enable plants to absorb micronutrients in the soil and retain soil moisture. Humic acids are commonly found in peat, manure, lignite coal and leonardite. They are sold commercially as a compost tea additive in powder form. When added to compost tea, humic acids can also act as food for the active microorganisms contained in the tea.
Add humic acid to your compost tea if your plants are having any disease-related problems and you need to boost water retention and nutrient absorption. You can also add humic acid to boost the fungal component in your compost tea.
Add the humic acid to your compost tea right before you apply the tea to your plants. You can add the humic acid as soon as the brew settles and is strained.
Mix in only one tablespoon of humic acid to about 5 gallons of compost tea, if the humic acid powder is a high-concentration variety. Stick with the 1 tablespoon of humic acid if the powder contains 85 percent or more humic acid and is 90 percent or more soluble.