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

PepTalk said:
Nice to see you are ready to Rock this project.   I have a small 15 gal set up now but would like to upgrade.
How does the AACT work out for you? I have only ever brewed enough to use on a handful of plants, this will be my first attempt at using on all of them.



Turns out I was wrong, I got the barrel filled last night and... yep, it is leaking again. I imagine I probably broke the seal putting it all back together. It was a really minor leak, and would probably run like that without issue, but it has been my experience that leaks only get bigger. I am going to reseal and retest today and tomorrow.
 
i havent followed the whole thread, so if its been mentioned sorry.

you should just try a uni seal.
if your at 1.5" just get a 1.5 inch uniseal and re drill it to like 2" or w/e the uniseal specifies.

uniseals are perfect for quick little knock out jobs like that. they are like 5 bucks for a big one... much cheaper than a real bulkhead. keep it out of the sun imo, they are supposedly very resiliant but idk.

ive used them several times for curved surfaces and they work exceptionally well. make sure to deburr the surfaces after you drill it out, as a rough surface will damage the seal when you remove it... making it harder to reuse the seal.

half round hand file is what i use for this. hdpe will clog the file so oil it first.

edit: half round file not half moon... where did i get half moon from?
 
queequeg152 said:
i havent followed the whole thread, so if its been mentioned sorry.

you should just try a uni seal.
if your at 1.5" just get a 1.5 inch uniseal and re drill it to like 2" or w/e the uniseal specifies.

uniseals are perfect for quick little knock out jobs like that. they are like 5 bucks for a big one... much cheaper than a real bulkhead. keep it out of the sun imo, they are supposedly very resiliant but idk.

ive used them several times for curved surfaces and they work exceptionally well. make sure to deburr the surfaces after you drill it out, as a rough surface will damage the seal when you remove it... making it harder to reuse the seal.

half moon hand file is what i use for this. hdpe will clog the file so oil it first.
Thanks for the input, I was actually hoping you would stop by at some point, I have a lot of respect for your knowledge of engineering.

I did actually end up going with a uni seal, it actually worked better than anything by far. The only reason it leaks a tiny amount after installing it, is because the bottom of the barrel isn't completely flat.

Like I said, one tiny spot that is still leaking, but another round of silicone should take care of it.
 
ah, sorry i havent had a chance to read this whole thread yet.


never had a uniseal leak on me yet, suprised you had a problem with them.
on the other hand ive never installed them onto the bottom of anything before.

it sounds like the bottom is not uniform? i havent worked alot with the hdpe barrels, ive been using the brute trashcans.

could the bottom of your barrel be bulging at all? its conceivable that you could add additional bracing across the bottom of the barrel to keep it flatter. i had a brute trashcan fail from the bottom due to insufficient support on the bottom.
it suprised me... i had two 2x4 members like 18" offset. the bottom essentially tore a small leak where the reinforcing meets the bottom of the trashcan.

a farther fetched idea would be to swage the end of the pvc that is mating with the uniseal. idk if you are familiar with how they swage exhaust systems for cars and such but you could just basically heat the pvc and jam something like a beer bottle into it forcing the pvc to expand ever so slightly... kinda sorta like a poor mans swaging press.

anyway... just expanding the pipe by a paultry 1/8" would vastly increase the pressure on the seal, thereby closing the small gap hopefully.

ive never liked silicone caulking tbh. it will work, but not forever. the guy who installed the plumbing for my moms pool equipment elected to just use silicone RTV on the threads insted of pipe dope/the good quality pink PFTE tape... needless to say ive replaced most of what hes done after just 7 or so years after numerous leaks.

on the other hand, this is likely not going to be around even a fraction of 7 years? idk.
 
queequeg152 said:
ah, sorry i havent had a chance to read this whole thread yet.


never had a uniseal leak on me yet, suprised you had a problem with them.
on the other hand ive never installed them onto the bottom of anything before.

it sounds like the bottom is not uniform? i havent worked alot with the hdpe barrels, ive been using the brute trashcans.

could the bottom of your barrel be bulging at all? its conceivable that you could add additional bracing across the bottom of the barrel to keep it flatter. i had a brute trashcan fail from the bottom due to insufficient support on the bottom.
it suprised me... i had two 2x4 members like 18" offset. the bottom essentially tore a small leak where the reinforcing meets the bottom of the trashcan.

a farther fetched idea would be to swage the end of the pvc that is mating with the uniseal. idk if you are familiar with how they swage exhaust systems for cars and such but you could just basically heat the pvc and jam something like a beer bottle into it forcing the pvc to expand ever so slightly... kinda sorta like a poor mans swaging press.

anyway... just expanding the pipe by a paultry 1/8" would vastly increase the pressure on the seal, thereby closing the small gap hopefully.

ive never liked silicone caulking tbh. it will work, but not forever. the guy who installed the plumbing for my moms pool equipment elected to just use silicone RTV on the threads insted of pipe dope/the good quality pink PFTE tape... needless to say ive replaced most of what hes done after just 7 or so years after numerous leaks.

on the other hand, this is likely not going to be around even a fraction of 7 years? idk.
Again, we are totally on the same page here, which I take as a good sign.

Correct, the bottom of the barrel isn't exactly uniform since it was re-purposed from a friend who was moving and was going to throw it out. Once the barrel is about halfway full it begins to bulge, which causes it to become even less uniform, causing the slow leak to start around one spot on the uni seal.

I was literally just putting together a plan to brace the entire bottom of the barrel to keep it from bulging. I think this is the key issue. The bulging is also putting a lot of stress on the intake of the pump.

If I can get away with not putting any silicone on it, it would be ideal. I agree, it is never a permanent fix. I don't necessarily think AACT is the end-all be-all of organic growing either, so I may run this thing a few times then throw it out anyway. It really will depend on results.
 
interesting, so this thing is basically a crude aerobic digestor. ive actually got a significant amount of experience working with sewage treatment plants. im actually just finishing up the cad work on a 100,000 gallon plant adapted to operate with covered tanks.

you are using a venturi for air flow? can you show me more about it? i cant seem to find any photos of the venturi.

heres what i can tell you regarding aerobic digestors... on the scale of a WWTP, many rely on mixing as accomplished accomplished by means of roll vortexing via a coarse bubble column that extends the legnth of the tanks.

this things looks like its gong to get plenty of actual agitation via that beef pump, but hows your aeration? i saw in the video posted earlier the vinyl hoses leading into the top that were very slowly bubbling... imo if that is the only aeration you have, you have too little.

you can get more air a few ways... venturies like you noted, or by pumping air...
with venturies obiviously you accrue alot of head loss, on the other hand you can add many venturies in parallel to lessen this... however a really good venturi is going to be spendy.

IMO... you should look too hot tubs. think about it, millions are sold annually... millions more are discarded each year. parts are going to be cheap. i have a 3/4 HP hot tub pump i picked up for like 45 bucks year or so ago...

i suspect you can find a blower for less than that.
perhaps some hot tubs incorporate venturies that you can buy second hand, idk. i do know that there are hot tub "jets" that have built in venturies that draw in air such that the jets shove out a decent stream of very very coarse bubbles.
imo these jets are not going to be suitable, bubbles will be to coarse. might be worth looking into however.

what i would look for is a real small hot tub blower, and some misc. hot tub parts to allow you to duct this into your pump discharge. its pretty much the same deal as a hot tub really. make sure to get a check valve for the blower.

OR some hot tub venturie parts. i dont think your pump is up to the task of pumping through a set of venturies however.
hot tub pumps tend to be closed type impellers which generate superb pressures and not so great flow rates.
irrigation pumps tend to be really sturdy open ended impellors designed to operate really flow hungry irrigation equipment, they dont generate very good pressures at an decent flow, so you will probably find that a venturie is not suitable.

but who knows, you may find parts that are perfect for you.

anyway to sum it all up... look to hot tubs, someone has done all the work for you already, just need to find some random parts.
 
Damn, I really, REALLY want to be DONE with this forum for a while, but I feel this is important enough to post one last thing.

At the moment I am not adding the venturis. Because of the beefy pump, the vortex consistently reaches all the way to the drain which is sucking quite a bit of air into the water at the moment. It will probably destroy the pump eventually, but for no more than I need it, it should hold up to a couple of days of abuse. My father's pool pump sucks air through the skimmer all the time and has been running for at least 10 summers in a row.

Here are the venturi tees I will install, one on each side outflow to aerate. I placed two on order last week, but I haven't received them yet. They are in fact, made for hot tubs. I also had the realization that I needed to start digging for hot tub parts.

Venturi.gif

http://www.lascofittings.com/Products/venturi.asp
 
 
I may come back and update this thread and check messages in a couple of days, but beyond that I am done with this place. Thanks for the help with this everyone!
 
lol is someone trolling you or something?

so wow, its vortexing all the way to the bottom? thats pretty cool.
you might consider adding a pair of bricks to the bottom. this would add a bit of baffling to the vortex.

those venturies look pretty much perfect...very large orifice. where are you going to mount them?

these things are puzzling to me.
why so much emphasis on vortexing? it seems to me like the whole idea here is basically no different than a sewage treatment plant.
you are basically breaking down complex organic crap into usable nitrogen phosphate etc by an aerobic organism. why does it have to vortex at all? seems to me like a good strong bubble column in the middle and occasional mixing the sludge with a paddle would work great.

whats the point of the vortexing? is it supposed to expedite the process or something?
 
I will definitely consider throwing the bricks in there. I think the draw to vortexing is that you want the tea to stay aerobic and, in theory, paddling may cause "dead spots" where the tea could become anaerobic. The vortex, in theory, shouldn't have any dead spots. It may also speed up the process, but I don't know for sure.
 
The only reason I went the vortex route, is the fact that the water will naturally want to vortex given top-to-bottom recirculation. I can actually stop the vortexing completely by changing the angle of the outflows, so I plan to try it each way. I definitely do not buy into this whole "earth energy" spiritual hippy crap that the manufacturers of the commercial brewers tout.
 
Compost Brewer.jpg
 
I was going to add one venturi to the main outflow at the pump, but instead I am going to place one on each arm that leads to the two outflows into the barrel.
 
the vortex will undoubtedly keep things well mixed, but such agressive agitation personally seems unnecessary, and to an extent counterproductive.

i guess im having trouble understanding what people do with these things

is this thing always running? are you always adding more waste to it, while simultaneously discharging to your fertigation system?

or is this like just a batch, that will be run and pumped out periodically and then shut down for a while?

do you decant the treated water? or maby floc it with some rice hulls or w.e? if so is this sludge then collected and recycled?

in a commercial WWTP the sludge collected can even be dried out mechanically for cheaper/ easier transportation to the dump or w/e. this dried slude i understand, can even be sold to nurseries/ farms etc.

edit:

oh and fwiw, a pump sucking a bit of air is not the end of the world TBH, i wouldnt go to the ends of the world to address it. unless its surging or free wheeling its probably not going to noticeably wear out your pump any sooner than it would otherwise.
just make sure to keep the shaft seal in very very good condition, when ever you are pumping anything dirty or abrasive or corrosive, you must be very careful to isolate the process water from the motor. they arent spendy,like 10 bucks for a new accordion type seal usually. its probably worth it to familiarize yourself with the manual for this pump.
in some really touchy processes, pump seals are actually pressurized with fresh tap water and allowed to leak ever so slowly into the process water, this assures no process water an leak into the seal and ruin like a fancy 15k dollar motor. the water pressure and flow of this seal would also likely be monitored through a fancy PLC system too.
if you can keep the motor going, usually you can replace everything else in due time without having to shell out big bucks for a whole new pump.
impeller... bushings.. seals,caps, bearings,even entire wet end assemblies can usually be replaced for reletivly little compared to a whole new pump... IF you take care of the motor.
 
To address what these are used for:
 
AACT is basically growing microbial colonies, that are found in compost, on a exponential level. The theory is adding healthy amount of the microbes to your existing soil will make more of the nutrients in your soil available for your plants. There is a lot of contradictory research on the pros/cons of the method, and as always, shady science on both sides. The main thing I am interested in is the water retention benefits, as I have sandy soil and I have been struggling with early season BER the last few years. There are some commercial AACT brewer systems out there, but they are in the $2000-3000 range for one this size.
 
The tea is brewed for 24-48 generally, then diluted (or not in some cases) and sprayed onto crops or run into irrigation systems. You brew one batch at a time, not constantly, and most people only apply it 1-2 times a month at most. I will also be looking into adding fresh fish puree as I have access to all the "trash fish" I want and the microbial colonies should break it down rather quickly, which sounds a heck of a lot better than leaving a bucket full of fish to ferment for a month at a time. Usually the "solids" (screened compost) are kept in some kind of strainer and not allowed to circulate through the system, however, most people use air pumps and venturi lifts to create the circulation which means they can allow free floating solids since they don't have to worry about ruining a water pump. I will be straining, plus I have a pretty fine mesh screen installed on the barrel drain.
 
Because of the overpowered pump, I will have to let it continue to circulate while pumping out to the fertigation system. I tried capping the outlets and discharging, and it was WAY too much pressure for me to feel comfortable with. With the circulation still open, the discharge pressure was roughly about the same as my water pressure from the tap. The only problem is that I won't be able to quite run it to empty, so some of the tea will get used for hand watering, which I am OK with.
 
The agitation might be overkill, that has been brought up before, but when I watch the videos of the commercial units, my system doesn't seem to be any more violent. Unfortunately the only way to tell is to go ahead and run a batch and see what happens.
 
My motor didn't come with any type of manual, it was just a cheap Chinese made motor my dad bought of eBay for next to nothing. It didn't cost me a dime so if I burn it out, I am not going to lose any sleep over it. I have noticed that most water pumps are fairly easy to repair/replace parts, which is part of the reason that I decided to go with a water pump over an air pump/venturi lift system.
 
Without further ado, here is the first video of it running, now leak-free
And now here it is running with a brick in the bottom per queequeg's advice
I honestly think I am getting more air with the disruption the brick causes. I am going to stick with the brick for now, mainly because I am letting the water dechlorinate right now and I don't want to go swimming to recover the brick! I start my first batch of tea tomorrow.
 
where are the bricks at? i dont think i mentioned it, but the bricks should legnthwise on the sides of the barrel.
 
take a look at this baffled reactor
510px-Agitated_vessel.svg.png

 
the baffles are supposed to be like up too 1/4 of the radius if i remember right.  with as many as 6 being typical in a big stubby tank like this picture. the baffeling actually makes the mixing process far more efficient. when you add aeration proper baffeling will increase the contact time of your bubbles.
 
on another note, according to everything ive read w/ respect to waste water treatment, all aerobic flora die off  in less than two days after being introduced into piping/ still tankage. it might be optimistic to assume you are introducing a massive heard of beneficial flora into your soil, but Idk this is apples to oranges.
 
also how does this stuff aide in water retention?
 
also how does this stuff aide in water retention?


By creating a biofilm, it's like putting a whole bunch of slime in your soil. The microbes produce it to keep themselves from drying out, thus = water retention. Also, ideally, you are also spiking the soil with mutualistic fungus that effectively increases the surface area of the root system. Some fungi even help the plants produce growth hormones. I read that for maximum fungal colonies to stop the process from 24-36 hours in, and for maximum bacterial colonies, you should let it go to 48 hours.
 
Just a quick update. I managed to run the brewer for 32 hours this weekend. I made a lot of mistakes from the beginning, the first of which was using a tea bag that had to large of a mesh. Within 5 minutes the screen at the bottom of the barrel was clogged and the pump quit running. I had to empty the barrel, by hand, into buckets since I had already added the fish and the molasses. That was a STINKY job!
 
Once I got that sorted out, the brewer ran without a hitch until it was time to pump it out to the irrigation. For whatever reason I had a lot of trouble finding a good configuration of pressure and release that would consistently pump through the drip tape without blowing caps off and such. The last 10 gallons has to be emptied by tipping the barrel out.
 
After 32 hours there was very little smell coming from the barrel, so I can only assume at this point that the brew didn't go anaerobic. There was also about 10 inches of head on the brew, which, from what I understand, is a good sign. Now we just sit back and wait for results.
 
Here is the brew after 18 hours
http://youtu.be/2DSq56hwlYE
 
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