Compost Tea Brewer




Introduction: Compost Tea Brewer


20 Gal. Rubbermaid Roughneck Trash Can - w/Lid - Model # FG289200BLA (Home Depot)

3- 1/2" Rain Bird 360 Spray Nozzle (Irrigation)

1- 1/2 PVC Sch 40 X 8'

3- 1/2 Tee

3- 1/2 Slip/Thread

2- 1/2 45

1- 1/2 Cap

1- 1/2 90

1- 1/2 MPT - 3/8 MPT Adapter

1- 3/8 MPT - 1/4 MPT Adapter

1- 1/4 Male & Female Quick Connect (Pnuematic)

1- 5-gal Bucket

1- 5-gal Paint Strainer (Elastic)

Step 1: Assembly

Cut 2 Holes 7/8" Adjacent (above Handles)

Measure, Cut and Assemble parts

I haven't glued yet, I kept everything dry fit to determine if I wanted any modifications.

I figured I would glue if it became an issue... It hasn't.

Step 2: Strainer Assembly

Pretty Straight forward -

Cut the upper 1/4 of bucket all the way around and remove the handle.

You can permanently affix the bag to the bucket top if you like but the elastic seems to hold fine for now.

I cut a slot in each side of the bucket to hold the compost bag in place, on the rigid pipe.

This was necessary to get the proper positioning of the bag relative to the bottom.

Design Explanation on prototype (5-Gal bucket with Air stones)

Upon experimentation (with clean water) I found that the bubbles were not penetrating the strainer, and more-so they were bouncing off on their way to the top. Also the foam overflowed every time.

Thus, this design was evolved to allow that center nozzle to be inside the bag to ensure proper agitation and oxygenation to the particles of compost throughout the brewing process, and the larger size allows for more brew and more room for foam.

The Air stones were benched, and replaced with irrigation sprayers, because I couldn't see them lasting very long, whereas the sprayers should have less or no clogging issues.

The 2 outer nozzles are to ensure there are no dead zones or anaerobic pockets were air bubbles aren't breaking the surface tension of the water.

This design seems to provide the best bacterial multiplication.

I went with a 951 GPH commercial air pump, If i had that to do over I might step it up a bit, but be sure not go under that.

I fill the water up to 8" down from the top, about where the inner bump (ring). This allows the foam to get a "head" but not overflow, which did happen in the prototype.

Step 3: Ingredients

Most folks use straight worm castings & Molasses for their tea, but others introduce several guano's for a cocktail of different bacterium.

I'm not sure that some of these don't cancel each other out, but regardless this is what I went with. My strategy was to strike a balance on the minerals with a variety of different bacterium, and hope for the best.

My tea is for tomatoes, most of what is out there on specific recipe's are for pot which is not yet legal where i live.

I don't purport to know what I'm talking about on the specific chemistry, so I won't be supplying a specific recipe.

I assume my plants will uptake what they want and discard the rest.

The focus of my build on the brewer was to get the most high-functioning unit for the cheapest OOP.

I would guess i have $30 bucks in the parts, and I'll put it up against the $300 commercial brewers out there.

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    Bille Nutmeg
    Bille Nutmeg

    4 years ago

    Looks very doable. I'll give it a good soon.