DIY Airlift/Vortex Compost Tea Brewer (5-gal)

SpicySativa

SpicySativa

Well-Known Member
What's up organic heads?

Seems like there's a lot of interest in AACT brews these days, so I just wanted to post up a couple pictures of my homemade airlift/vortex AACT brewer. The design is a mixture of other DIYs I've seen, with a little of my own flavor added in.

I have monitored dissolved oxygen levels over several runs, and the DO saturation does not seem to dip below 99% saturation (about 9 ppm at approximately 70* F). All connections are slip-fit (no glue), meaning it takes about 5 minutes to break it down, give it a quick scrub with a bottle brush, and plop all the pipes and fittings into a bucket of dilute bleach for a quick soak. Then less than 5 minutes to reassemble, rinse, and repeat.

The pump I use is an EcoPlus Air 5 Commercial air pump. This pump REALLY gets things moving. The "cone" of the vortex actually stretches all the way down the tank, so air bubbles are getting drawn DOWN through the drain hole.

The design should be pretty self explanatory, but let me know if you have any questions!

IMG_8673.jpgIMG_8678.jpgIMG_8682.jpgIMG_8681.jpg
 
SpicySativa

SpicySativa

Well-Known Member
Parts list off the top of my head...

-1x Water jug (w/o handle)
-2x milk crates
-4x 1.5" PVC Tee fitting
-1x 1.5" PVC elbow fitting
-2x 1.5" 45 degree elbow fitting
-1x stick of 1.5" PVC (8 or 10 ft, it's cheap)
-1x 1.5" PVC ball valve
-1x 1.5" rubber coupling with hose clamps
-2x 1.5" rubber caps with hose clamp (cut holes in these, slightly smaller that your air hose for a snug fit)
-Air tubing and Tee fitting (I used 1/2" ID tubing for my Ecoplus Air 5 pump)

Not all milk crates are exactly the same. First cut the hole for the mouth of the jug to pass through. Install the rubber coupling an the bottom Tee fitting, THEN cut the holes for the risers to pass outward through the milk crate after you see where they should align.

You'll need a jig saw, some sand paper, and a screwdriver for the hose clamps.

I think I covered everything... I'll double check when I've got the brewer in front of me.
 
Kevdogg5555

Kevdogg5555

Well-Known Member
lets see a brew is action. Im still trying to understand the concept of the vortex. I see there is a vortex created inside the 5 gallon, but how does the help the tea. (keep it oxygenated, tea last longer?)
 
SpicySativa

SpicySativa

Well-Known Member
The vortex keeps everything suspended and well mixed (which prevents anaerobic zones from forming). You don't use a "tea bag" with brewers like this, and having that mixing action keeps everything evenly mixed. The vortex also helps keep DO levels high by exposing more water surface area to to air, and by actually sucking air bubbles down through the bottom drain.

I'll snap a few more pics during my next brew. I just took those vortex pics using plain water because you can't see shit once the water is brown and frothy.

As far as how long the tea lasts... AACT does not last... Period... Tea is a constantly changing, living entity. When I turn off the air pump, dissolved oxygen levels immediately begin to plummet as the biology uses the oxygen faster than it recharges at the water surface. Also, the biological makeup of the tea changes over the course of a brew cycle, so there is really just a small window when the tea is "ready" (this window changes depending on all kinds of factors, including what you WANT in your tea).

Give this a read:

http://ecologiesurleweb.free.fr/docs/Docs_agir/Lombricomposteur/Brew Manual compost tea.pdf
 
Crab Pot

Crab Pot

Well-Known Member
Great looking brewer... How far are you placing the air tubing down through the rubber caps?
 
Crab Pot

Crab Pot

Well-Known Member
SpicySativa said:
The tubing goes about 3/4 of the way down the airlift tubes. Once you fire it up, it's easy to lift or lower the tubes to fine tune the pumping action for the most flow, and to keep it even between the two legs.
Click to expand...

Thanks SS! Just waiting for the water bottle...
 
S

solst1ce

Member
chbk said:
Yes a elemental 1157 gph.it's been in use a while that was a older picture.
Click to expand...
I'd like see it if you have a picture...
Using 4 (or 3) legs so it supports itself is a nice design- but I'm not understanding how you are piping the air into the lift tubes.
can you explain how that is done?
 
Bobotrank

Bobotrank

Well-Known Member
Hey Spicy, great DIY thread. I'm trying to figure out if I want to build something like yours with 2 airlifts, or go with 4, a la versions I've seen elsewhere online (and via Microbeman's website). I guess as long as you're reaching 9ppm by the time you're harvesting the tea it shouldn't really matter? I like the way your spout comes out… it looks like no tea could get left behind in the bottom of the airlifts like with other designs I've seen (the 4 lift that someone posted a picture of ^^^^ , specifically)...

Here's my real question, though: I've noticed that some people throw airstones on the end of their tubing inside of the airlifts… Are you using stones? I would think it would only improve the DO levels in the brewer. Just more to clean/replace over time. Thoughts?

Thanks again for posting this. Peace bro.
 
N

normalus

Member
good quality bucket, cheap plastics it is not so good. i heard wooden box is good for brewing teas. So good bucket and bubbler of some kind, not too big not too small. that is i think this is waste of time but if you have nothing to do it could be fun project.
 
SpicySativa

SpicySativa

Well-Known Member
I don't use air stones in the ends of my tubes. I have seen no need to add them; my DO levels stay PLENTY high already.

As for 2 airlifts versus 4, I find 2 airlifts to be more than sufficient. Like I said, my DO levels are maintained at just about the saturation limit. You can't go any higher than that, no matter how many airlifts you add...

Long story short, I think adding 2 extra airlifts or adding airstones is just giving yourself more stuff to clean after each brew.

If it ain't broke, why fix it?
 
Bobotrank

Bobotrank

Well-Known Member
Thanks, Spicy. My thoughts exactly. I went down the same rabbit hole you did, and constantly kept coming back to your design. You thought of everything that needed to be fixed, plus no airstones (as I suspected). Stones are bullshit. No matter what you do, they tend to only worsen in little time. Pains in the ass to clean, too.

Peace.
 
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