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50 Gallon compost tea brewer - need a sanity check from AACT brewers

theghostpepperstore

theghostpepperstore

So I am in the design stage of putting together a compost tea brewer. I have a bit of experience brewing compost/worm tea, but nothing on this scale. I know that most everyone uses large air pumps for gas diffusion, but I have a different idea. I am hoping some of you that brew AACT a lot can give me a sanity check.
 
Here are the requirements for the brewer:
  • Needs to be overkill - 5 gallon buckets are not enough, but I probably wont go through 40-50 gallons either
  • Needs to be cheap - I realize I can buy a kit for around $600, so I need to be way under that number
  • Final product needs to be pumped directly out to the garden - I don't want to fill a backpack sprayer 10 times, or carry buckets around, plus since I already have irrigation, makes sense to just pump it straight into the system. (Maybe figure out a way to dilute in the process?)
 
Here is a diagram of what I am thinking
Compost Brewer.jpg

 
Now, I know the first thing that everyone is going to jump all over is the lack of an air pump. The way I figure, I have to put a water pump into the mix to accomplish requirement #3, so with venturi carburetor, the vortex, and breaking the surface tension, I think I will be able to get the gas diffusion I need. I am open to arguments on this, but if I have to buy a $100 air pump AND a $100 water pump, that might blow requirement #2.
 
I plan to hang the tea bag from a piece of 3/8" threaded rod running through the top of the bucket. The pump I am looking at should be able to handle a small amount of solids, but nothing larger than coarse sand.
 
Like I said, this is all in the design stage right now, so if anyone has thoughts, I would love to hear them before I start working on the construction.
 
Since you already have the irrigation system set up there are set ups you can get or make yourself that will siphon off your tank or bucket to you main line without using an additional pump. I'm planning on doing the same. Their intended use is for fertilizer obviously but should work as long as you don't plug up the line with particles. Then you could buy a large air pump and stones for well less than the cost of an additional pump and brew the tea as you would normally. I'm getting 4 55 gal drums when I get off work in a couple wks, mainly to use as a resivoir for my hydro set up to automatic keep their level while gone but I was planning on saving one for the same purpose as your thinking. Good luck. Drip works sells the kits and all parts to make these inline setups.
 
Seacowboy said:
Since you already have the irrigation system set up there are set ups you can get or make yourself that will siphon off your tank or bucket to you main line without using an additional pump. I'm planning on doing the same. Their intended use is for fertilizer obviously but should work as long as you don't plug up the line with particles. Then you could buy a large air pump and stones for well less than the cost of an additional pump and brew the tea as you would normally. I'm getting 4 55 gal drums when I get off work in a couple wks, mainly to use as a resivoir for my hydro set up to automatic keep their level while gone but I was planning on saving one for the same purpose as your thinking. Good luck. Drip works sells the kits and all parts to make these inline setups.
Click to expand...
 
Good suggestions!
 
I do already have two different types of fertilizer injectors that I use with my current setup. One is a 3/4 gallon EZ-Flo that I use when adding straight ferts, and a venturi siphon injector that I rarely use because the mix ratio is too high for organic ferts.
 
The problem with both of them is the lowest ratio I can get out of either of them is 1:100 (I think), most of the people who use AACT use it at 1:2 - 1:4. The simplest way around this is to just brew 25 gallons at a time, then fill the barrel, giving me 1:2 then pump it straight out. I could even pump it down to 12 gallons, reserving the rest in buckets, then fill the barrel and run 1:4 or whatever.
 
There is also the possibility of just connecting the outflow to the venturi carb and letting the pump mix it, in theory, I should be able to tell what the flow rate through the venturi is and adjust with a regulator to get the desired ratio.
 
Unfortunately I'm no hydraulic engineer so I wouldn't even try to guess on pipe/hose size to get your ratio lower. I see 2 options. 1- if you know your current rate in gph through the line play with pipe size and time it to see how long it takes to drain the 50 gal drum and go up or down in size to make it equal to desired ratio. 2- figure out you irrigation line capacity. Drain it then flood it with straight tea then flush with desired ratio of water. Again you'd have to know you rate for this and you may get more or none in certain places depending on your set up.

That's at least how I see it from the outside looking in.
 
I agree. Luckily from what I understand about AACT, it doesn't hurt to use it uncut, and people dilute it to make it go farther. Its nutrient content isn't so high that it would burn any plants. Some of it will always get used as a foliar before running through the irrigation but no where near all of it. 50 gallons run through my system should provide plenty to each plant. With all the rain we are getting, flushing water behind it won't even matter.
Jeff, it is not much more complex than the average brewer. From what I have seen, I would need something like an 85watt air pump to supply enough for AACT brewing at 50 gallons. Then, I still end up needing a water transfer pump to get it out to the plants.

Adding an air pump is plan B, but I would like to skip it if I can.
 
I use my 5 gallon tea uncut to feed my 12 plants every year. After a few shots of tea they go absolutely crazy and grow like all heck.
 
The only thing I would be worried about is whether it has too much pressure for the bacteria in the brew?
If the water is excessively turbulent there's a chance of killing the microbes as it can literally tear them apart.
Not sure at what point it's too turbulent though as that would take some trial and error and a 400x microscope.
 
Thanks, that is the one of the things that has been hard to find answers about. I have seen lots of discussion about different styles of water pumps and different theories on which ones are safer. Unfortunately there doesn't seem to be a consensus. Centrifugal pumps seem to be OK as long as they don't "cycle" the same water for a long time, which I don't think will be a problem. Diaphragm pumps don't have a lot of turbulance inside the pump but they create high pressure which could destroy the microbes inside the piping.

I read some research that showed the pressure coming from the outlets at the top of a vortex brewer isn't enough to destroy microbes, but may destroy the fungal hyphae. Of course I also understand that micro-spraying even at low pressure and destroy the fungal growth.

I guess I will just have to build this sucker and find out. It seems like there is going to be quite a bit of trial and error.
 
"I guess I will just have to build this sucker and find out"
 
Can't wait to see this get built.
Keep us updated and good luck.
 
It looks like this project is definitely a "go". One of the great things about having a pack-rat in the family, is that when you mention your hair-brained schemes during family gatherings, you quickly find yourself a truckload of free parts. My father just happened to have a brand new water pump lying around. Now it looks like I just need to pick up a few PVC parts, and I should be on my way to mocking everything up this week.
 
 
The biggest problem I see at the moment is the "free" pump has a max flow rate of 40gpm, which is pretty high. That would recycle the entire contents of the barrel every 75 seconds! I may have to install a motor speed switch to turn down the speed of the motor, or I can increase the amount of head.
 
From the hydraulic performance chart for the pump (xkp450) , it looks like if I can increase the head to about 25ft then I will get a lot slower recycle rate. Anyone got any ideas for increasing the head?
 
6-1-2.jpg
 
So I started mocking this sucker up tonight. I only managed to get one side outlet put together. Who knew a 45 elbow + a 90 elbow does not add up to a 180 degree turn? Oh well, just need to grab a couple more tomorrow.
 

Untitled by GhostPepperStore.com, on Flickr
 
I went ahead and just put together a top outlet real quick to get an idea of how fast this pump was going to mix the barrel. I actually think the rate is about right. The vortex was pretty strong to begin with and was causing the vortex to suck all the way down to the pump. When I put my hand where the compost tea bag would sit, it breaks it up enough to fix it. I also was able to adjust the angle of the jet to get a slower spin.
Thoughts?
 
So here is my big brewer running with both side outlets and the tube on top that will ultimately run straight into the tea bag to help push the microbes out into the mix.
I still don't have the carburetor figured out. I made a couple attempts at it, but it seemed to really stress the motor and didn't seem to create a significant amount of additional bubbling. 
 
Another test that didn't go well was testing the outflow that will be connected to the irrigation system. I capped off all three outlets in the barrel, then opened the drain valve. The PVC reduces from 1.5" to 3/4" then to a copper hose thread adapter. Since everything is still just a "mock up" none of the PVC is glued at the moment. The increased pressure, along with the unsecured PVC caused one of the outlet arms to blow off, smacking me in the face at a rather high velocity. Dumb mistake, for sure, thankfully I am not very pretty to begin with, so no real damage done.
 
The pressure at the hose end is WAY too high with the outlets capped, but if I leave them open, it is just about right. I think that will have to be the method, though I think I will not be able to drain completely since at some point so much air will enter the pump that it will cease to stay primed and stop pumping altogether.
 
I guess I really need to see if I can find a meter for DO2 so that I can see if I am getting enough oxygen in the water. The last thing I want on my hands is 50 gallons of anaerobic tea to get rid of.
 
I figure I should update this, since progress has been slow but steady.
 
After about 8 trips to the hardware store, and many attempts at piecing everything together, I just about have this figured out. Unfortunately working full time and running two businesses has really limited the amount of time I have to work on it. Almost all of the PVC is glued down. One of the fatal flaws has been the fact that the position of the drain on the bottom actually changes as you fill the barrel with water. The bottom of the barrel deflects by about two inches once it is full, causing stress on the plastic intake of the pump. It might have made more sense to go with a flexible reinforced hose rather than PVC, but for now, I think it is going to work.
 
The other problem has been keeping the drain from leaking like crazy. I am using all 1.5" PVC, so the outside diameter of the male threaded end of a 1.5" slip on adapter is 1.875". I used a 2" hole saw, leaving me a 1/8 inch gap that has proven rather difficult to seal. I found some big rubber gaskets that have a 1.875" hole and are 4" wide and even with one on each side of the hole, it still leaks. Yesterday I used some silicon to seal the gaskets against the barrel, and the male adapter against the lower gasket. It should be nice and set today, so hopefully I can just screw the female adapter down on the inside and be done with it. I also added a screen made from window screening to the female adapter and secured it using a hose clamp.
 
Hopefully pics of the final product soon.
 
Was going to message you later today to see how it was coming along. Sounds like you got it about nailed down. I hope to pick up my barrels later this week and one I am going to reserve for trying this out once you get all the kinks worked out for me. ;)
 
Yeah, good thing I updated it today, I just saw a message on YouTube from ProgressEarth asking me to NOT call it a "Vortex Brewer"... Fair enough, they do own the trademark, so from now on this device will be referred to as a "tourbillion brewer"
 
So I finally got a successful pressure test out of this contraption. Everything is now glued down and ready to rock. Going to get it all together tonight and dechlorinate some tap water. It is supposed to be relatively cool for the next week, so it sounds like a perfect time to start my first brew in it.
 
theghostpepperstore said:
So I finally got a successful pressure test out of this contraption. Everything is now glued down and ready to rock. Going to get it all together tonight and dechlorinate some tap water. It is supposed to be relatively cool for the next week, so it sounds like a perfect time to start my first brew in it.
Click to expand...
Nice to see you are ready to Rock this project.   I have a small 15 gal set up now but would like to upgrade.
 
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