Backyard Aquaponics
A place to discuss aquaponics

Very cute.

So this mean that acid is what keeps the compost hot TC? How does this affect the compost worms do you think? Maybe keep to the edges? Safe to add to vermicompost?
Was wondering if dumping urine straight into the AP system could bring a pH down safely.........

no urine is not acid!

Part of urine changes to urea and the urea changes to ammonia which is high nitrogen which will really heat up compost. If you don't have enough high carbon cover material to balance the high nitrogen then you will notice the odor and know you need more high carbon material in the compost. Many home composters have trouble getting hot compost when all they are piling up are things like yard waste and brown leaves. If they ask me how to make their compost hot, I send them out to pee on it.

As to how worms deal with urine or hot compost, they try to escape it. A worm bin is not the appropriate place to hot compost (this is why they always tell one to avoid feeding worms too much at any one time because it could cause the bin to heat up) In a worm bin you want to make sure there is always a cool moist place for the worms to go in case the "feed" area gets too hot for them. As to urine, I think what worms dislike about urine in the immediate sense is probably the high salt content it usually has. I've read on other forums where some one was trying to use their worm bin to deal with their body waste (I do not advise this) they found that the worms would happily work on poo and toilet paper but found the worms would fee the bin (and wind up dried worm sticks all over the floor) if they peed in it. Reasons for the worms to flee the pee, in a plastic worm bin the primary reason would be too wet (read becomes anaerobic) and too salty, with a little time the urine becomes more ammonia and that can in such high concentrations be bad for the worms tender skin as well as for many of the microbes that the worms depend on to survive.

Worms and many other compost creatures do not enter or work on compost until long after the "hot" compost stage. Good compost takes a lot of time and the hot compost stage is relatively short.

As to the pH effects of urine. The pH of urine comming out of a body will vary depending on the person and their diet but it is usually not too far from neutral. If you put urine in a bottle for a period of time (say a week to a month depending) the pH will rise as the urea is converted into ammonia (the enzyme that does this is generally already present in the urine) when the pH reaches 9 most (though perhaps not all) pathogens likely to be in urine are killed off.

So, would adding urine to an AP system adjust it's pH? Well, If you added enough of the aged stuff to adjust the pH up you would likely be adding so much as to kill off the system and create a stinking mess. Now on the other hand, we know about the bacteria action causing an acidifying effect on a system. I can tell you that when I initially cycled my barrel ponics system (when it only had river gravel as media, no shells) using urine as the cycling neared completion, the pH of that system did drop dramatically to the point that even with our hard well water, I still needed to buffer the system to keep the pH above 7.

Urine is not an acid, it is an ammonia source (as well as containing other nutrients.)

I noticed that the people doing tot long term composting toilets use a small variety of worm that can handle high nitrogen environments. Also, I noticed they added a mist sprayer in the bin. Perhaps this is how they keep it worm friendly.

Urin is collected in a tank and taken to local farms.

In a continuous compost pile (one that stuff gets added at the top of the pile without turning the pile over) there are usually cool areas around the edges that worms could escape to. Or in outdoor ground compost bins, the worms can wander down into the soil as needed and come back up to eat when conditions are right.

TCL.....DDM....interesting topic - have to try some of the ideas.

DDM......re:smell. I add a teaspoon of Iron Chelate to about 1/2 gal. of urine....stops smell immediately/long term
will turn urine black - good/bad....I dunno?
Might solve your smell problem.

I really dont think urin smell will be a problem. As 70% or more of the nutrients are in the urin I plan to use the urin on a daily or weekly basis. Its not going to be stored. Fresh urin will pass down through the pile and through a bio filter then to a collection barrel.

Watched this "e2" program on PBS, about the White Lotus School in Ladakh, in Tibet. The building was designed with multiple sustainable principles like solar design, local materials, etc. The restrooms were composting as there is not much water around the area, there is a cross section if you click the VIP latrines link on this page:

http://www.dwls.org/Sustainable-Design-Examples.html

Dan,
I am curious about a couple items in your design. Primarily, the urine that passes through the pile to be collected. What about pathogens? What research is there on that subject directly pertaining to this design.

I know that separated urine (not contacting other possible pathogen containing materials on it's way to storage) when sealed up to reach a high pH can kill off most (though perhaps not all) pathogens.

There are more variables in an unsealed storage of short duration with urine that has been heavily pre-contaminated with any possible contaminants.

I did some experiments back around the time of starting the pee ponics experiment. I found that fresh urine can support and grow fecal bacteria while if sealed up and stored for a few weeks the urine turning into ammonia managed to kill off most of those fecal bacteria.

This may be something you want to research further before fertilizing your veggie garden with urine freshly passed through the humanure pile. Perhaps a bottled and sealed period of a couple weeks before use would be worth researching.

Then again, If you have a substantial amount of cover material for absorbing odors, you might find there is only minimal leaching of liquid out the bottom of the pile.

Good luck with it.

I suspect that there will be minimal liquid collection. None-the-less, having read what you discovered about stored urin I do plan on leaving it caned for some time to kill any pathogens. 2 tanks with a 3 way valve to change to flow from one tank to the other.

BTW, I have recently stated making flutes from hardwood and I am saving the saw dust. I can see that it does not take long to make 5 gallons of fine saw dust, lol. Perhaps I can avoid having to buy sawdust. There is a small mill near by, but they process mostly pine.

Also, what about cedar saw dust; is it ok to use?

According to the forum over at Jenkins web site, hardwood sawdust is the best for humanure composting but I've found that pine, cypress and probably even cedar will also work (they just don't break down as fast.)

Sawdust from raw wood (before kiln drying) is also better though the dry stuff will work too though it might require more of it to cover odors or take a little longer for it to absorb moisture. (That whole dry powder effect of repelling rather than absorbing moisture.)

There are all sorts of things people have tried for cover material. Leaves, shredded paper, peat, rice hulls, straw, coffee grounds, etc. Many of them work to an extent. Sawdust seems to be the best all around if one has a cheap or free source for lots of sawdust. Leaves and shredded paper can be good for a coarse cover material but something with a dustier texture tends to cover the stinky #2 deposits best. We tend to use shredded paper to cover liquid and toilet paper additions to the buckets and use sawdust to cover other stuff.

For your set up, you will have to work out what system/methods work best for you.

Here you go, put a charcoal urinal next to your sawdust poo bucket. Use the charcoal as a soil amendment:

http://e-biocharurinals.blogspot.com/

Heck, you could even just use sawdust or whatever in the urinal and use it as a soil amendment, no need to get too fancy. Heck, the compost that comes out of the humanure composting pile makes a really good soil amendment, just takes a little time. It is important that some of the urine makes it into the regular humanure compost because it is the urine that allows it to get hot and compost properly. Turds in sawdust don't compost very well, usually too dry and not enough nitrogen.

Hi all,just for intrest, a friend of mine is spreding a few hundred tons of human manure on some guys property north of perth as a trial, he was saying that they add a heap of lime to kill of the bugs and then add clay to it, I think he said they were going to trial oats in this field and do heaps of tests as it grows( for contamination). His bobcat was covered in it, i nearly died when he grabed a big chunk of it and tried to hand it to me smell this he says with a big grin, funny thing was all you could smell was the clay

Should work just fine TEA...the Chinese/Vietnamese etc have been using "night soil" for centuries...