DIY Compost Tea Brewers/Mixers

After discussion with my friend Stewart Lundy, I thought I'd share this video on the construction and operation of a couple of compost tea brewers I put together with his help. The idea was that we wanted to have a very simple brewer with as few moving parts and accessible as possible to clean given that we want no anaerobic microfilm build-up after a brew. We use an airlift pump in both the 7 and 35 gallon brewers. The airlift pump both aerates the water and ensures that microbes are not damaged in the pumping process - the vortex is also a great place to add any new solids. The addition on flex hose, suggested by Stewart Lundy was a gamechanger (in my first design I used PVC pip fittings) that allows one to quickly and conveniently (and without mess) empty the tank. I don't know if adding more hose to allow several twists to the system may help and if directionality (clockwise or anticlockwise) counts, but for now the system works.
Kudos to Lizbet Palmer from www.wayfaristm... who did the camera work.

[@sandysmagicmix]

That looks like a good design. Thanks for making this video.

[@malcolmbronte-stewart2114]

I have looked at so many different compost tea brewer designs - this must be the best of all, so straightforward to build, use and clean.

[@hughgoble]

Many thanks, Buzz! Now I know how I need to build my mixer

[@Buzatesri]

You bet, Hugh. I am not the most practical/handy person in the world, so this ought to be a breeze for you.

[@mslabber1028]

Thanks, this is nifty!

[@Buzatesri]

Glad this helps, hope you are well!

[@thingformob]

Really like it. Thanks

[@jancornelis378]

Thanks for the detailed instuctions. I used your video this weekend to make a similar model. It's way more turbulent and choppy than yours, so I have to figure out why. One question: why are we not just putting the air hose in a bucket with water and compost? Why does the water have to circulate? Would the action of the air bubbles alone not be enough without the circulation to break up the glomalines that bind the microorganisms?
Jan

[@erikreuterskiold5996]

Airlift + vortex has been shown to generate the highest dissolved O2 in the water, higher than just bubbling

[@jancornelis378]

@erikreuterskiold5996 I didn't know this. Thanks for the explanation!!

[@erikreuterskiold5996]

What size/capacity pump do you recommend for a 30 gallon build? What specs on what youre using in the video?

[@fukyu3424]

Why do we ground the rig? Thanks for the video!

[@Buzatesri]

I was told by a biodynamic farmer that this will reduce potentially pathogenic microbes in the mix (e.g., E. coli). I haven't ever tested this idea myself but I figured it wouldn't hurt. I do pay attention to making sure that the system is aerobic - if you have access to a DO meter, keep DO levels above 7ppm. This is easier to do when its cold simply because DOsat is higher in cooler temps, lower in warmer temps.

[@gregtomilson3846]

Where can I get one of those conical vessels?