tutorial Beginner's guide to AACT/Compost Tea

ColdSmoke said:
 
amen to that. I know folks (who's livelihood are on the line, ie store owners) who consider "true" aact to be EWC, guano and kelp with molasses as the food. I guess it depends on who you learned from and your preference. 
What do hydro store owners know? I go by what Dr. Elaine Ingham and other soil biologists say as these are the people who pioneered AACT.
 
Proud Marine Dad said:
What do hydro store owners know? I go by what Dr. Elaine Ingham and other soil biologists say as these are the people who pioneered AACT.
they know what works. Splitting hairs over extra "ingredients" just to stay true to the name is futile for everyone involved. 
 
ColdSmoke said:
they know what works. Splitting hairs over extra "ingredients" just to stay true to the name is futile for everyone involved. 
I'm just telling you what AACT is thats all. Hell put any damn thing in it you want it doesn't matter to me. If you have a viable soil AACT isn't even necessary.
 
So you think two plants with viable soil in containers would yield the same if only one received aact throughout  the season?
 
I don't think the AACT would increase the yield no.
Living soil already has a soil food web in place so why give it more microbes? I have not tested it but I think using AACT on a soil that already contains a healthy microbe population could possibly be counter productive.
 
I think adding AACT to a healthy living soil is going to provide a boost to the local microbe population through an influx of readily digestable food (ie. microbe cannabalism and residual carbohydrates), leading to an increase of plant available nutrients, uptaken as needed. A bit of conjecture, still reinforcing the basics and absorbing as much information as I can when I can.
 
 
ColdSmoke said:
they know what works. Splitting hairs over extra "ingredients" just to stay true to the name is futile for everyone involved. 
 
I usually advise keeping things simple until you understand the impact of added or substituted ingredients. Example, kelp.
 
Kelp meal - 0.25% max. [Less is more!]
NOTE:This is a maximum amount of kelp and you can experiment using less. This is using regular grade kelp meal for livestock. If you have soluble kelp, I recommend using smaller amounts. Sometimes kelp meal can initially delay bacterial multiplication. - Tim Wilson

 
And his research continues, recently on his forum he raised the issue of kelp meal and the potential to feed anaerobic bacteria in badly designed brewers. As well, I know he routinely waters with AACT on his farm where I would think his soil is thriving with life.
 
Another example, the fairly common substitution of honey for molasses, something many people do but few look into the potential effect, which is quite obvious after a very short web search.
 
The reasoning for this hair splitting is simple. If you don't know the proportions or effect an ingredient will have, why add it until you do? A quick browse through a couple dozen "DIY" recipes found here and elsewhere is reason enough to question if anyone actually thinks about what their doing or just looks at AACT as the organic version of a bottle of food.
 
Just for kicks, ask the grow store owner what function the guano serves? I've always been confused about it's addition and put it down to the pot grower ideology of force feeding nutrients. But then, trying to increase the nutrient value of tea equates to a misunderstanding of its purpose...
 
 
I was going to put a post-it on the my monitor, "Be less of a prick", but I know it would just lead to a fight with the idiot who put it there.
 
I was thinking about guano recently, and I think it can be considered food for the microbes (which in turn releases nutrients), although I imagine you would need to brew for awhile for it to be of any use.
 
miguelovic said:
 
I was going to put a post-it on the my monitor, "Be less of a prick", but I know it would just lead to a fight with the idiot who put it there.
Classic!
 
Honestly, I think it's just what he learned and has worked for him. I know he switches guanos based on their NPK at certain stages if that tells you anything. He's using it as fertilizer to it appears.
I thought guano added bacteria to the mix...
 
ColdSmoke said:
Classic!
 
Honestly, I think it's just what he learned and has worked for him. I know he switches guanos based on their NPK at certain stages if that tells you anything. He's using it as fertilizer to it appears.

I thought guano added bacteria to the mix...
 
They do, but as you just said yourself the hydro store guy switches guano based on NPK. ;-) That means in addition to adding to the microbial population it also adds nutrients after being processed.
 
filmost said:
 
They do, but as you just said yourself the hydro store guy switches guano based on NPK. ;-) That means in addition to adding to the microbial population it also adds nutrients after being processed.
seems like compost and castings do that as well, no?
 
ColdSmoke said:
seems like compost and castings do that as well, no?
 
Good point, and now we have circled back around. LOL.
 
In any case, I believe that the main use of AACT is adding microbes to the soil. And if brewed long enough, it may also add nutrients. I mean I can't imagine anyone getting tons of nutrients from a 24-48hr brew. Then again perhaps it has just the right amount of nutes in that time span. I have no way to test this though.
 
Anyone else want to chime in here?
 
miguelovic said:
I think adding AACT to a healthy living soil is going to provide a boost to the local microbe population through an influx of readily digestable food (ie. microbe cannabalism and residual carbohydrates), leading to an increase of plant available nutrients, uptaken as needed. A bit of conjecture, still reinforcing the basics and absorbing as much information as I can when I can.
 
 
 
I usually advise keeping things simple until you understand the impact of added or substituted ingredients. Example, kelp.
 
Kelp meal - 0.25% max. [Less is more!]
NOTE:This is a maximum amount of kelp and you can experiment using less. This is using regular grade kelp meal for livestock. If you have soluble kelp, I recommend using smaller amounts. Sometimes kelp meal can initially delay bacterial multiplication. - Tim Wilson

 
And his research continues, recently on his forum he raised the issue of kelp meal and the potential to feed anaerobic bacteria in badly designed brewers. As well, I know he routinely waters with AACT on his farm where I would think his soil is thriving with life.
 
Another example, the fairly common substitution of honey for molasses, something many people do but few look into the potential effect, which is quite obvious after a very short web search.
 
The reasoning for this hair splitting is simple. If you don't know the proportions or effect an ingredient will have, why add it until you do? A quick browse through a couple dozen "DIY" recipes found here and elsewhere is reason enough to question if anyone actually thinks about what their doing or just looks at AACT as the organic version of a bottle of food.
 
Just for kicks, ask the grow store owner what function the guano serves? I've always been confused about it's addition and put it down to the pot grower ideology of force feeding nutrients. But then, trying to increase the nutrient value of tea equates to a misunderstanding of its purpose...
 
 
I was going to put a post-it on the my monitor, "Be less of a prick", but I know it would just lead to a fight with the idiot who put it there.
You are right with the guano mentality coming from some in the pot growing industry. Nobody really recommends it in the organic pot growing forum I participate in so I don't know why it's touted as being so great.
filmost said:
 
Good point, and now we have circled back around. LOL.
 
In any case, I believe that the main use of AACT is adding microbes to the soil. And if brewed long enough, it may also add nutrients. I mean I can't imagine anyone getting tons of nutrients from a 24-48hr brew. Then again perhaps it has just the right amount of nutes in that time span. I have no way to test this though.
 
Anyone else want to chime in here?
But the point of making an AACT is not to add nutrients, it's to multiply the beneficial bacteria by feeding them carbohydrates and oxygen. If you want nutrients put it in your soil where the bacteria in the soil can break it down and make it available to the plant.
 
Atleast in common proportions (around 2.5%) for a brew I couldn't imagine the nutrient load being very high. Compost/castings nutrient values are usually below 1% for each major element, so you'd be looking at a small fraction of a percentile.
 
Guano as I understand it is mined resource from old bat caves, far from a fresh state that would have had microbes present. Much as oyster shell flour comes from old sea floor deposits as opposed to freshly ground oysters. It may feed microbes in a similar fashion as say glacial rock dust, but the proportions needed to avoid disrupting the microbe-brewing process, with its high level of nutrients, would negate it as a nutritional amendment. Atleast to my current understanding.
 
Top dressing is my go to method of adding nutrients, lightly worked into the soil, followed by tea to enhance breakdown. I understand his (grow store) philosophy, my first brews contained guano, among many other things, but the more I read/learn the less I add, and in small proportions. Accessing different forms of microbe innoculants (raw sphagnum, fresh [unbagged] compost/castings, forest floor duff, garden soil) has replaced the old desire to ensure maximum nutrients are getting to the plants through tea.

Proud Marine Dad said:
But the point of making an AACT is not to add nutrients, it's to multiply the beneficial bacteria by feeding them carbohydrates and oxygen. If you want nutrients put it in your soil where the bacteria in the soil can break it down and make it available to the plant.
 
Huzzah!
 
That was a good read by the way Mike. I have also been cutting down on things I added to my brews, but I didn't know there were ideal proportions. Usually I just grabbed a handful and stuffed it in mesh. Will try my next brew(s) with his proportions and try the pre-feeding bit with my not so fresh EWC.

Oh a different note, do you guys get a lot of goopy stuff on the surface of your air stones? How are you cleaning them? I have been scrubbing it off mine and letting the airpump run in tap water with a little hydrogen peroxide added in.
 
filmost said:
That was a good read by the way Mike. I have also been cutting down on things I added to my brews, but I didn't know there were ideal proportions. Usually I just grabbed a handful and stuffed it in mesh. Will try my next brew(s) with his proportions and try the pre-feeding bit with my not so fresh EWC.
Oh a different note, do you guys get a lot of goopy stuff on the surface of your air stones? How are you cleaning them? I have been scrubbing it off mine and letting the airpump run in tap water with a little hydrogen peroxide added in.
I quit using airstones for that reason. Now i use 14$ worth of drip irrigation that i made a maifold out of. It has about 30 pin sized holes that surround the bottom of my bucket. I now get bubbles around the entire bucket. The slime just wipes off the smooth surface.
 
filmost said:
That was a good read by the way Mike. I have also been cutting down on things I added to my brews, but I didn't know there were ideal proportions. Usually I just grabbed a handful and stuffed it in mesh. Will try my next brew(s) with his proportions and try the pre-feeding bit with my not so fresh EWC.

Oh a different note, do you guys get a lot of goopy stuff on the surface of your air stones? How are you cleaning them? I have been scrubbing it off mine and letting the airpump run in tap water with a little hydrogen peroxide added in.
An overnight soak with oxi clean free will do the trick. Half gallon of hot water with a TBL of oxi clean free. Rinse good and run them for an hour, good to go. If they are still clogged let them soak longer.
 
I've been poking around a bit more on honey, and found the below article a very interesting read, though it confirmed many previous assumptions.
 
Much of the antibacterial effect is from a high sugar content, low pH and natural H202, though testing with manuka (peroxide free) in varying concentrations shows strong effect from other constituents of honey.
 
It appears the H2O2 effect can be mitigated through heating or bubbling/sitting out, say, while you dechlorinate. The concentrations required to have a broad spectrum antibacterial effect range from 3.5-100 percent, with different varieties and qualities having vastly different effect.
 
Looking at it's effects on B. subtilis, a common soil microbe and commercial innoculant, at very low concentrations, it would seem simpler to just avoid it altogether when possible, or to use mass produced pasteurized honey if necessary.
 
Honey - its medicinal property and antibacterial activity
 
MIC (minimum inhibitory concentration) values of honey extracts were found in the range of 0.625–5.000 mg/mL (0.0625-0.5%), for S. aureus, B. subtilis, B. cereus, and gram-negative bacteria, E. coli, P. aeruginosa and S. typhi.
 
Parentheses added.
 
Cayennemist said:
I quit using airstones for that reason. Now i use 14$ worth of drip irrigation that i made a maifold out of. It has about 30 pin sized holes that surround the bottom of my bucket. I now get bubbles around the entire bucket. The slime just wipes off the smooth surface.
 
Wicked, I was just about to swap out the stones for something similar. I was thinking it might have a lift effect on the outside rim that would increase circulation?
 
Applied my first aact last night. It was just 1.5 cups each of compost and ewc with two TBS of molasses. The bucket smelled like bait container of night-crawlers. I assume this is good? The earlier batch I made with a million ingredients fed some hop plants and some rose bushes. It will be hard to tell what good it does, comparatively speaking, because last year was the only time I've grown peppers and I put almost zero effort into it. This year, I'm putting significant efforts and doing a ton of things differently, not just aact.
 
miguelovic said:
I've been poking around a bit more on honey, and found the below article a very interesting read, though it confirmed many previous assumptions.
 
Much of the antibacterial effect is from a high sugar content, low pH and natural H202, though testing with manuka (peroxide free) in varying concentrations shows strong effect from other constituents of honey.
 
It appears the H2O2 effect can be mitigated through heating or bubbling/sitting out, say, while you dechlorinate. The concentrations required to have a broad spectrum antibacterial effect range from 3.5-100 percent, with different varieties and qualities having vastly different effect.
 
Looking at it's effects on B. subtilis, a common soil microbe and commercial innoculant, at very low concentrations, it would seem simpler to just avoid it altogether when possible, or to use mass produced pasteurized honey if necessary.
 
Honey - its medicinal property and antibacterial activity
 
MIC (minimum inhibitory concentration) values of honey extracts were found in the range of 0.625–5.000 mg/mL (0.0625-0.5%), for S. aureus, B. subtilis, B. cereus, and gram-negative bacteria, E. coli, P. aeruginosa and S. typhi.
 
Parentheses added.
 
 
Wicked, I was just about to swap out the stones for something similar. I was thinking it might have a lift effect on the outside rim that would increase circulation?
 
If you added the honey in the same ratio as the molasses then would it not be well below that concentration range i.e. 0.2mg/ml? So should be OK?
 
I know kelp (Laminaria digitata) has various antibacterial compounds such as polyphenols, in addition it contains fucoidan a heavily sulphated polysaccharide, which is believed to be antimicrobial as well - hence why low amounts might give better results - but most of the polysaccharides will be probably end up as either mannose, glucose, and oligosaccharides of these (derived from the laminarin) gluronate, mannuronate and oligosaccharides of these (from the alginate) and fucose, gluronic acids and oligosaccharides of these (from fucoidan) - Basically lots of lovely substrates for bacterial and fungi growth!!
 
A worry for me is, it seems to me to be a rather simplified distinction between good and bad microbes i.e. aerobic good/ anaerobic bad - which is rarely the case in other applications/microbiomes
 
An immediate concern would be the risk of producing pathogens from the spores within the manure or other environmental sources. I would recommend using gloves and washing well after using it!!!
 
I carry out a lot of bacterial fermentations and lots of things can go wrong, and that is using sophisticated laboratory equipment costing 100,000's of dollars, never mind a home made fermenter!! So, I would expect a huge variation between people's AACT even from AACT's brewed in the same town using the same ingredients.
 
But it is a interesting topic for me, which I will be giving a go. I might try to alter some of the conditions using my knowledge from my work, but the question remains other than seeing how the plants grow - we do not know what the ideal microbial composition is and even if we did I doubt anyone would be forking out 75,000 odd dollars to sequence the bacteria in your AACT to find out whether the bacterial composition is beneficial or not.  :P
 
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