Organic gardeners the world over know that compost tea can benefit most any organic garden. Making compost tea is a simple enough process, as long as you have the correct compost tea making supplies. You need to decide if you want to make Actively Aerated Compost Tea, a compost extract, or a compost leachate.
Actively aerated compost tea, or aact, is made by introducing air into the water and also adding food for the microbes to feed off of. With the increase in oxygen, and a good food source, the microbes in the compost will replicate and fill up your tea with dense microbial activity.
A compost extract is where you extract the microbes form the compost into water, and then soil drench this liquid. This can be as simple as adding compost to a compost tea bag, dipping the bag in a bucket of water, and then messaging the bag for a few minutes to release the microbes, humic, and fulvic acids into the water.
A compost leachate is an older version of making a compost tea. You simply fill a bucket with water and soak a bag of compost in the water. It is always a good idea to massage the bag of compost and help the process along so that you can get the max amount of microbes and nutrients into the water.
Choosing the right compost for your compost tea's shouldn't be over thought. It is always better to use multiple different compost sources then to stick with just one. Worm castings are a solid choice for making teas, but it is always a good idea to alternate between compost sources with different brews. Maybe you have a fungally dominant compost you want to use, then alternating this with a bacterial dominant brew can help to introduce a wider range of microbes & fungi into your soil. Diversity in the soil should be your main objective with your compost teas.
When making aact's you will need a high quality air pump, and some sort of bubbling stones, wands, or other air introduction contraption. Pairing an air pump with some basic aquarium air stones is an easy way to get started with making compost teas. Using multiple air stones tends to work better than 1 giant air stone. It makes it so that you can adjust the air flow better in your brew. Make sure you get plenty of air line to connect your air pump to your air stones, and also that you have a splitter if you are wanting to use multiple air stones with a single outlet pump.
Air stones come in small 2” size bars up to 12” giant discs. Depending on the size of brew you want to make you may want to fashion pvc pipes into your air discharge device. By making a pvc discharge device you can brew in 32 gallon trash cans, 55 gallon drums, and even 275 gallon IBC tote tanks. For larger farms or gardens this is a good option so you aren't brewing small brews all the time. You can do one big brew and your entire garden is covered. Again, buying an air pump with the right air flow is critical to making any brewer work.
Choosing an air pump for your compost tea brewing isn't that hard. Just remember to always go bigger than you think you will need as you can put a regulator valve in line to adjust the air flow as needed. Air pumps are either measured in Liters per minute, or gallons per hour. For a 5 gallon compost tea using an air pump in the 600 gallon per hour range is a good start. Jumping up to around 1000 gph isn't a bad idea as you can regulate down the air flow if needed. Then if you decide to brew 2 buckets at 1 time, or brew 10 gallon brews your pump will have enough air flow to accomplish that goal.
Adding air to an aact is only part of the equation for producing a high quality compost tea. You will also need to add a food source for the microbes to feed off of. Fish hydrolysate, seaweed, and molasses are standard in most brews. Dry fish amendments don't work very well for compost teas that's why everyone tends to use a liquid fish fertilizer product. When it comes to seaweed, a liquid kelp product works very well, but you can also use kelp meal as an alternative. Your microbes will also need a sugar source, and the industry standard is molasses. It's shelf stable, readily available, and works very well. As an alternative dried molasses works and doesn't create a mess like liquid molasses does.
Once you have your compost, air pump, air stones, and microbe food, you are ready to brew an actively aerated compost tea. Attach your air stones to your air pump and air line, and place the stones in the bottom of the bucket. Fill the bucket with dechlorinated water, and add your microbe foods. Suspend your compost in the water, and begin to bubble your bucket. You will want to bubble your bucket for a minimum of 24 hours, but to produce a quality compost tea you may need to bubble it for up to 48 hours. Air temps, wind, starting and water temperature all play a factor into how long your compost tea will take to brew. Once your tea is done brewing, you can remove the air stones, and the bag of compost and apply your tea full strength to your garden.
Application rates for compost tea can vary a lot. Some people think that you should water down the tea to extend how far it will go, but this defeats the purpose of making a high quality compost tea. If this is your logic I would stick with a compost leachate. Using compost tea monthly or even weekly will show an improvement in most organic gardens, lawns, and gold courses. If you are growing hemp, cannabis, or marijuana then using a compost tea as part of your regular standard operating procedures can help to keep your plants healthy and push the terpene profiles of your finished flower.
No matter the application, using a compost tea in your organic garden is a natural way to introduce microbes that can in turn increase nutrient cycling, which will make more nutrients bio-available to your plants. It really is a simple way to improve the overall health of any garden, and it's soil.
