There’s been a great conversation happening in the comments lately. The topic is Actively Aerated Compost Tea. AACT is a great way to create microbial colonies that thrive on oxygen and deliver many benefits to the root zone.
Red Myst writes:
I am growing in a home-mixed organic soil that’s based on 50/50 mix of cocotek/sunshine peat moss. Added to this base was earthworm castings, Ancient Forest, perlite, pumice, Fox Farms Ocean Forest, Organicare Indoor Aeration Mix, Royal Gold Basement Mix, and a blend of dry organic fertilizers including a 4-3-6 ‘Tomato Tone’ fertilizer, Peruvian seabird guano, Jamaican and Indonesian Bat Guanos, Kelp Meal, Dolomitic Lime, Green Sand, and MgO. It is a rich soil that will usually get me into early flowering without need for extra feeding, but I still like to add Bio Root and Superthrive(drop a gallon) to at least every other watering and administer foliars using Nitrozyme marine algae product every 7-10 days.
I am now 1/3 to 1/2 way into fruit production I am alternating watering with a G.O. BT Bloom, CaMg+, Bio Bud combination and a Jamaican or Indonesian bat guano tea. I alternate between these two cocktails. I just recently decided to brew up the humus tea, figuring it could only help break down and make available whatever still remains in the soil, and I really wanted to introduce Floralicious Plus to see what kind of a difference it makes in flavor.
This brings up a question I’ve been contemplating. The Ancient Forest humus tea instructions say to brew at least two or three days. If I want to go longer, can I(or should I) add a little black strap molasses to the brew to ‘feed’ the microbes, or will they be okay without it. If so, how often and how much? Also, how long can the tea be brewed (and maybe topped off with fresh H2O, humus and/or Floralicious Plus) before you would recommend starting a fresh batch? Okay, so maybe I have a few questions;-)
Lastly, I just took some of the 2-day humus tea brew today (1 gallon) and added it to 2 gallons of straight R.O. water. I then added BT Bloom, CaMg+ and Bio Bud at moderate label rates. The pH of this mix was pretty low (around 4+/-), so I raised it back to 6-6.2 using Potassium hydroxide. So, the question is: Did I kill off or injure my microbial population with this move?
Okay, that’s it for now. Thanks for your magnificent support!
And the answer from our own Randall:
Wow, that soil mix your’re putting together is RIDIC! Now that is some diversity. As you state, this is a RICH mix which does not require much ‘feeding’, although adding BioRoot early on is a great idea, and you can add a little more than 1 drop per Gallon. Try 1-3 tsp per Gallon. I would even suggest a VERY LIGHT application of BioThrive Grow during your short vegetative stage.
The Kelp foliar spray you apply every 7-10 days is also great. I love Kelp (BioWeed) as a foliar spray @ ½ tsp per 1 Liter of good water. I would ONLY do this during vegetative growth and I stop foliar feeding during flowering. AACT as a foliar spray during vegetative growth is a great plan.
You are halfway into your flowering stage, using the GO line along with 2 kinds of Guano AACTs, and you are now brewing up AACT with the Ancient Forest. You are correct that the AACT will help breakdown and make available nutrients and supplements to the plant, along with increasing the plants root growth and biological diversity in the soil mix, helping to increase the overall potential and vitality of the plant.
When you are growing a plant in soil, it is almost like the plant itself is secondary to the soil and the biology in the soil. Provide a nice, diverse range of microbes in the soil, add, enliven, and feed the microbes with AACT, and thus: FEED THE SOIL. Feed the soil, feed the microbes in the soil, and they in turn feed the plant. The symbiotic relationship of soil microbiology to plants roots is paramount! Plants roots give off sugars, called ‘exudates’, which soil microbes eat. The soil microbes eat the plant exudates, and the waste product provided by the soil microbes is the food and fuel for the plant. There is an element of communication at the root zone were plants give off specific exudates for specific microbes. You are enhancing and encouraging this with high quality organic soil mix, Ancient Forest, and AACT.
The microbes cultured in the Jamaican and Peruvian Guanos will be different from the microbes in the Ancient Forest. AF will potentially have more biological diversity in a AACT brew, however, each base food source for AACT, whether guano, manure, castings, or humus, will provide specific benefits for soil and plant growth. Basically, it’s hard to say one is ‘better’ than another due to the infinite amount of variance in specific gardens and plants. Generally, the more biological diversity, the better. AF contains a wide variety of different kinds of beneficial bacteria and fungi.
A big factor is the food (energy) source you use to ‘feed’ the microbes of the AACT. You add dormant microbes (from the AF, Guano, compost, etc.) to good water and add O2 with an air pump, which ‘wakes up’ the microbes from dormancy. What you provide as a food source for the awoken microbes will determine the diversity of microbes that will be cultured in the AACT, along with the amount of TIME you brew your AACT.
Floralicious Plus may be the best food source for AACT. It is comprised of extremely high quality complex sugars, vitamins, polysaccharides, fructans, humic/fulvic acids, plant/marine extracts (and much more) to feed and sustain beneficial microorganisms. Another suggestion for the food source for your AACT is FloraNectar, our sugar and carbohydrate supplement. FloraNectar contains high quality cane sugar, molasses, malt syrup, vitamins, minerals, and more. Both of these GH products will make an EXCELLENT food (energy) source for the microbes of AF or any other AACT base. (1-3) oz of either FP or FN per (5) Gallons of good water as an AACT food source.
OK, answers to your questions. #1, you ask about the amount of TIME necessary to brew AACT. Basically, you need to brew your AACT at least 6 hours, and you can brew AACT for up to three days. I would not suggest going longer than 3 days. Keep in mind that the longer you brew your AACT, the less microbial diversity your brew achieves. The brew evolves toward a monoculture with more TIME. This is because with time, different microbes will eat and replicate and outcompete different microbes, so over time, certain microbes can dominate the brew, making it a monoculture. This can be a bad thing. Not to fear, just don’t brew longer than 2 or 3 days at the most. Personally, I prefer to brew my AACT for 12-24 hours, no longer than 1.5 days. If you wanted to go longer, you can certainly add molasses and other food sources to the brew, but I would not go longer than 2 or 3 days. If you add molasses, 1-3 oz per 5 Gallons of water is good, just make sure the molasses is organic. When you are adding food sources to the AACT, be conservative with feeding.
#2, I would brew a batch of AACT for 12-36 hours and then start a new batch. Remember that the TEMPERATURE of your water plays a HUGE roll in so many aspects of AACT brewing and root zone ecology. Keep the water consistent at the 65-72 degree F range.
#3, Yes, you killed/injured/lessened the efficiency of your AACT by adding Potassium Hydroxide to your Tea. OK, so keep in mind that we are dealing with soil and root zone ecology here. We are dealing with millions of microbes and a ton of LIFE all up in your soil. Allow the life in your soil to balance itself out! In Hydroponics, the pH of your water is a fundamental factor as it allows access of nutrients to your plants in a water based growing environment, void of beneficial microbes. Without a balanced pH in hydroponics, plants will not be able to uptake nutrients as efficiently. pH in soil gardening is NOT as fundamental to successful gardening as pH is in hydroponic gardening. Soil microbiology has a lot to do with this. This is not to say pH is not vital and extremely important in soil, I am suggesting that it is not as fundamental to soil agriculture as it is in hydroponic agriculture. I am suggesting to not add pH up and pH down to AACT. The soil and the microbes can act as a pH buffer. Fluctuation in pH level may even be beneficial as it allows different nutrients more availability at different pH levels. Not to say you should allow your pH to get to 4 or 8 without concern, or that you should not monitor your pH. The point is that you should monitor your pH but NOT react like you would in a hydroponic scenario.
In soil, I find that pH range can be as great as into your mid to high 4’s upwards to your high 7’s. I have grown healthy and vibrant plants in soil with pH levels of my water source, that in hydroponics, would not fly. This is the beauty of the microbes in your soil. Let the microbes in your soil and your AACT balance your pH, rather than adding chemicals to artificially raise or lower your pH. That said, I also have clients who will have a very low pH in their feed water in soil and they will add a small amount of pH UP with success, so it is not like you eliminated your usage opportunity by adding pH UP, I just would not recommend it. I would follow the plant in this situation (and most situations). Plants never lie, they will tell you when they are happy, and they will tell you when they are sad. React to plants more than act. If you are in mid flower, using the same RO water and AACT, etc, and your garden is thriving, I would roll with the AACT with a low pH, rather than adding pH UP.
Good luck with your garden, Red Myst! Keep us updated on your progress!
Randall’s Recipe for Actively Aerated Compost Tea
(5) Gallons of good water
(3-5) cups of Ancient Forest
(1-3) oz of Floralicous Plus {OR(1-3) oz of FloraNectar OR (1-3) oz of organic Molasses OR(1-3) oz of BioWeed (Kelp)}
Good Air Pump
Brew it for 24 hours.
You can mix and match those food sources, if you do, always be conservative with dilutions (less is more!). If you add fertilizers like GO BioThrive and or GO BioBud to the AACT, use LESS than the suggested recommended dosage.
A light foliar spray of the AACT is great during vegetative growth
Kelp as a food source for AACT will culture a fungal dominated Tea.
Molasses and Sugars as a food source for AACT will culture a bacterially dominated Tea.