Aerobic Compost Tea Brewers, Keeping It Clean
By Elaine Ingham, Phd.
We've been documenting that people aren’t cleaning their compost tea brewers adequately. Whenever the first compost tea you make in a brewer was the best, and then the teas get worse and worse from then on, the take-home message is: NOT CLEANING PROPERLY.
Think about your compost tea as if you were getting ready to make something that you are going to drink. If your cleaning isn’t up to making the container something you would drink from, you are going to have problems with the quality of your tea. Run your hand over the surface of the brewer after you have water-blasted the tank "clean".
Is it "slimy"? Then get the 10% bleach or 2-5% hydrogen peroxide or OxyClean or ammonia – alcohol solution out and get to work washing down the tea brewer until the slime is gone.
Remember, anything that has been inside the brew has to get washed as well. The inside of any part that was in the tea brewer has to be cleaned. That means the INSIDE of any pipes, diffusers, bags, containers, aerators, or whatever you have in the brewer.
Monitor the quality of the tea you make with the small microscope. You can figure out activity by monitoring with time. Once the biomass of bacteria, or fungi, or protozoa does not increase in time-series samples, the organisms are not growing rapidly anymore. If numbers, or biomass, maintains at a certain level over time, the number of reproducing organisms equals the number becoming inactive (running out of food, oxygen, space, or being eaten). If biomass or numbers is decreasing over time, then death is occurring.
As your tea quality goes from good to ok, to poor, to bad, the take-home message is that you have an anaerobic bio-film someplace. You are going to have to find it. And get rid of it.
Author Elaine Ingham, soil researcher, Chief Scientist at Rodale Institute in Pennsylvania.
Soil Health Topics
Composting tips and working with "good guy" fungi.