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#131 - DIY 25-Gallon Compost Tea Brewer

79.4We all know the benefits of using compost and worm castings in our gardens and plants, but many people are not aware of another way of using compost that is even more beneficial to your plants. 


For those interested in a more natural or organic method of gardening, one of the most important things that you can do to help your plants thrive is to use compost teas and worm teas. In order to do that, you need a way to brew the compost tea or worm tea and that is what we are going to discuss today.


As some of you know, I have a Ph.D. in microbiology, so I understand the complexities of the biological ecosystem at the microbic level that is at work in the soil and interacting with our plants.


Many people think of plants as having roots that are basically one-way highways to deliver nutrients to the plant. The truth is it actually goes much deeper than that and as we are only just beginning to understand in the past few years the plants are actually communicating with the micro-organisms that live in the soil around the roots of the plant.


In exchange for the micro-organisms delivering nutrients to the plant roots to feed the plant with, approximately 40% of the sugars produced through photosynthesis in the plants are sent back down through the roots to feed the micro-organisms in a highly effective symbiotic relationship. The other 60% is used by the plant for growth, fruit production, etc.


The more beneficial micro-organisms living around the plant roots the better able the plant is to have access to the nutrients in the soil, so by using compost and worm casting teas we are adding billions of beneficial micro-organisms to the soil around the plants roots.


So, why would you want to use compost tea?  The nutrients in compost tea are more readily available to plants than those found in dry compost. The beneficial organisms -- which include bacteria, yeasts and fungi -- that compost tea provides your plants helps suppress diseases by either creating a physical barrier against disease-causing pathogens or by competing with or attacking them. Adding compost tea to your soil also reduces the need to use synthetic fertilizers, and it helps improve plant growth and vigor. This improved health reduces the risk of plant death due to pests or diseases.


Compost tea when added to the root zone of plants has also been shown in university studies to cause vigorous root development in plants which enables the plants to be more drought tolerant.


Compost teas can either be applied to the plants as a foliar spray or applied to the root zone around the plant. Im my case, I use both methods. Once per month I apply a foliar spray to the leaves and stems of the plants and I follow a weekly root zone application schedule.


Over the years I have tried multiple types of tea brewers and brewing systems, many of which have been quite expensive. They all had their good points, as well as their drawbacks or limitations. 


I finally found a home compost tea brewing system that incorporates the benefits of several of the other brewers that I have used over the years. However, this one doesn't have the drawbacks that they did. This is a tea brewer that you can build yourself right in your own home, and most of the parts to build it are available at Home Depot, Lowes, City Mill or just about any other hardware or home improvement store.


The best part of it is that you don't have to just take my word for it that it works. This particular compost tea brewer was designed by the Oregon State University Extension Service in Eugene, Oregon.


Even colleges and universities are recognizing the benefits of using compost teas for organic gardening and are devoting their resources to studying the benefits of using compost tea on crops to provide larger root systems, bigger harvests, less plant disease, and less damage from insects.


Not only did Oregon State University design one of the best compost tea brewers that I have ever seen, they made it available to everyone for free as Open Source so anyone can make one simply by clicking on the PDF link below to download the plans.

I have been borrowing the one pictured below for a couple months now to test it out and see how I liked the design and I decided that I liked it so much that I wanted to go ahead and build my own to see how difficult it is to build.

Once I had assembled all the necessary parts, following the PDF design supplied by Oregon State University that I posted above, I was able to cut all of the PVC pipe pieces and build the entire 25-gallon Compost Tea Brewer and have it functional in under 10 minutes by myself. It is extremely easy to build.


The compost tea brewer uses a 32-gallon Rubbermaid Brute commercial trashcan as the brewing tank. I also installed an optional ball valve at the bottom of mine to drain the compost tea from the brewer with.

PVC pipe is then used to create the air tube system inside the brewer tank. The system is designed to inject air from the ring in the bottom as well as from the vertical tube in the center into 25-gallons of water that is sitting inside the brewing tank. 

The resulting aeration of the water is quite effective.

Either compost or worm castings are then placed inside an extremely fine mesh heavy duty bag like the Bioextractor Bag shown below made by Biological Systems, LLC which I ordered from DripWorks.

The Bioextractor Bag is attached to the horizontal pipe above the water with the builtin straps with buckle clip on the bag. This is absolutely the highest quality compost tea brewing bag I have ever had the privilege to use. It is a little expensive, but with normal use you can tell that it is made to last for years.