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DIY Compost Tea Brewer: How to make a compost tea brewer on a budget. (Under $50)

Jeremy Silva |

Update: We are always learning and have since found new information. 


So you want to brew your own compost tea huh? Well I can’t blame you. This stuff is better than anything you can pay for and will all the misinformation surrounding compost tea it would be foolish to have anyone else make it for you.

BEWARE of the Myths

1. Worm juice leachate is the same stuff.

No – Worm leachate is anerobic and not even close.

2. You’re supposed to put guano and nutrients in the tea.

No – this is compost tea. Not nutrient tea. The Nutrients will ruin the development of your diverse tea.

3. I can just buy bottles of Compost tea or Worm tea on ebay or online…. Why make it?

Tea doesn’t last and as soon as you stop brewing it you should use it right away. Never bottle it.

4. The guys on youtube promise excellent compost tea with a small aquarium pump.

Please avoid listening to any of this information. The best tea is proven to be made with a dissolved oxygen level above 6.0 ppm and the small aquarium pump isn’t even close. You might even make a tea that could cause problems in your garden. If you have to use an aquarium pump with a cheap airstone then keep the brew to a 1-2 gallon size, maybe a milk jug.

5. It’s finished when all foamy and sweet smelling, right?

No! It’s done when it’s done and without a microscope you should achieve the best results following the recipe in our Blog article, http://buildasoil.com/blogs/news/8322788-how-to-make-compost-tea-in-3-easy-steps

Now that you know about the myths, let’s get down to business.

The cheapest way to make a decent tea, without buying a microscope to verify, is to follow a proven recipe.

Here is a cheap method that will work just fine.

Purchase List:

1. 5 or 6 gallon food grade plastic bucket with lid. (Home Depot or Lowes $4.00 - $6.00)

Grower Pro Tip: You can get these for free at bakeries, restaurants etc. 


2. High Quality Air Pump: EcoPlus Commercial Air pump #1 will work for up to 15 gallons. ($35.00)

3. SweetWater Glass Air Diffuser: Highest quality best air stone on the market. 6” (few bucks) Google them and you will find a store that carries a few sizes.

You want the barb to fit into your tubing. (Sweetwater Air Diffuser, 6" L x 1.5" W, 1/2" NPT)

EDIT: The Above pump is rated at 1.34 CFM and the Sweetwater airstones are rated for specific cfm. Not only will this make the airstone produce larger airbubbles than normal, it will also produce back pressure on the pump and this will wear it out prematurely. This can hopefully be fixed by using 2-3 Airstones or purchasing a larger Airstone from sweetwater. Feel free to email me with questions. I'm no expert on the subject, but I don't want to spread any misinformation. 

4. PVC or ½” ID Braided Clear Tubing. Enough to go from your pump to the bottom of your bucket. (Few Bucks at ace hardware)


5. 1 or 2 Metal Clamp thing for the tubing to connect to the airpump and PVC or tubing.


Now that you have your items it’s time to put it together.

Do this anyway that you want. It’s simple. Google Compost tea bucket and you will get some ideas. Just don't short yourself on cheap pumps or a cheap air stone.

Connect the air stone to the Tubing or PVC and set the airs tone in the bottom of the bucket.

Run the tubing out of the bucket and connect to your air pump.

A few things about the air pump:

-        Remove the factory brass nozzle on the air pump and put the ½” ID tubing over the top of the small round male part where the air comes out. This will increase airflow dramatically!

-        You have to have the air pump above the tea bucket or you run the risk of ruining the pump when the power goes out or turns off.

You can leave the lid off and brew tea, of you can cut a hole in the lid and run the tubing for the air stone through the lid. The reason for this is that with only 4 gallons of water in the bucket it will still foam up and possibly overflow a little foam onto the floor.

Once you have your bucket setup with the powerful pump and proper diffuser air stone it’s time to brew some tea!!!

Remember, we have an article on brewing your own tea over here --> http://buildasoil.com/blogs/news/8322788-how-to-make-compost-tea-in-3-easy-steps


If you want to be positive that you have the best tea. Then you should get a microscope and do some serious reading. Otherwise I hope the above information was helpful in getting you started.




Another great way of doing this. Get some PVC and make a simple airlift and use a clamp to keep it in place.



Video of it in action:


I dont understand how the airstone attaches to the pvc piping set up in you diagram. I see a 1/2 barb to 1/2 threaded fitting…then what? the airstone goes on the inside of that fitting?


Hello Mr. Wood,

Your welcome!

Cleaning, take it apart in the sink with hot water and clean it really quickly. occasionally I’ll use Hydrogen Peroxide or bleach to clean the whole bucket and airstone etc but it really isn’t that hard to clean.

You don’t need a bag to hold the worm castings as the airstone is constantly pushing air out of it and won’t clog. That’s part of the reason for ordering that sweetwater airstone.

In Fact, the mesh bags often stifle the fungi growth and that alone is worth having no bag for me.

Absolutely!!! Keep all the solids in the tea and dump them into your plants when watering.

I’m excited for you!!!

Please, if you build one, take a photo and let us know how it goes.

Call me at 970-306-7645 or email me at Jeremy@BuildASoil.com with any questions you have during construction.

Thanks for the questions!!!


Thanks for the article. I appreciate your specific recommendations for the pump & diffuser!

- any advice on cleaning? wipe the tubing, and soak the diffuser in 3% hydrogen peroxide?
- I read your post on teas. No mesh bag in the brewer? No problems with the solids clogging the diffuser? Is it OK to keep the remaining solids in the tea if I am going to pour tea on root zone (no spraying)?


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