alright people this is a little tutorial i'm putting together to show how to easily build an airlift
for brewing aerated compost tea (ACT)
if you wanna learn about compost tea and/or compost tea brewing systems, i suggest you check out microbeorganics.com
. after reading through that site and the sticky: tea article
thread in the organic soil forum, i designed this simple system.
first, i decided the airlift style brewer
had several advantages, most notably, breaking the water's surface tension. you can read the details on microbeorganics.com
, but basically it increases the amount of dissolved oxygen in the water, which is the aim in an ACT system. another good reason is that the vortex
and the microbulator
, two of the cooler commercially available systems, both use airlifts to drive their brewers.
the great thing about this is that it's entirely scalable
. i'm making one for a two gallon
container, because that's enough for my small garden. if you want to brew larger batches, you'll want a higher flow rate, so you'll need something stronger than any of the petco aquarium pumps. check microbeorganics.com
for a comprehensive guide for selecting the right air pump for your system.
are cheap and simple. the ten dollar cost does not include an air pump by the way. i had a petco "60+ gal tank" aquarium pump [5 watt]
, and that seems to work okay for my two gallon brews. for the pipe i used 1 1/4" pvc
. you should make sure your pipe is long enough to reach near (but not sitting on) the bottom. you'll need a 180* turn, so you can use two elbows, or get a "p-trap" set like i'm using. it's for kitchen sinks, and has the advantage of an adjustable joint with a silicone o-ring that makes cleaning really easy. you'll also need fasteners
like rubber bands and velcro, or whatever you've got.
assemble the p-trap. two
bundle the air hose from the pump together and loop the bottom 8 - 12", securing it with a rubber band 1.5 - 2" from the ends.
fasten the loop near the bottom of your pipe and the hose once or twice more up the length of the pipe.
slip the ends of the air tubes inside the end of the pipe. use the tension from the rubber band to pinch the edge of the pipe so the air tubes will stay in place. you want to get the ends of the tubes as close to the bottom of the pipe as possible while staying securely inside.
that's it! now rig up a way to secure it in your bucket, fill up to 2-3" under your spout, and mix up your tea!
i made a brace
. i took an extra length of pvc and cut a slit in either end. the slits fit over the sides of my bucket. i used heavy duty velcro to fasten the airlift to the brace.
this brewer is designed for use without a bag
. just add your compost directly to the water. edit: the term is free suspention
for your reference, here's the basic recipe
as perscribed by microbeman
in the sticky: tea article
Originally Posted by Microbeman
1 gallon = 16 cups = 256 tablespoons
2.38% by volume compost or vermicompost (EWC) per gallon = .38 cups or around half a cup max or about 2 cups in 5 gallons max.
0.5 to 0.75% molasses by volume per gallon = 1.28 to 1.92 tablespoons per gallon. 0.75% is the maximum I use. It is a good bacterial and fungal food.
0.063% fish hydrolysate by volume per gallon = 0.16 tablespoon = 0.479 teaspoons or half a teaspoon
0.25% (max) kelpmeal by volume per gallon = 0.64 tablespoon or half a tablespoon
happy brewing! stay green!
EDIT: I'VE UPDATED MY DESIGN. TWO AIR PUMPS. DRILLED HOLES AT THE BOTTOM OF THE LIFT TO HOLD LINES, CUT OUTS BETWEEN AIR HOLES TO ALLOW WATER IN ABOVE THE BUBBLES.
Originally Posted by heady blunts
thanks to rip van weed for the clever idea. it really improves the flow (and hopefully circulation)!
plus i fashioned a much better brace to keep the air lift upright.