Backyard Aquaponics
A place to discuss aquaponics

There is no such thing as a 'stocking density' with peeponics.
And the bacteria grow to adjust to increased ammonia supply.

So if you gradually increased the dosage, how far could you go?
Certainly the bacteria will reach a population limit but I think with any sized gravel growbed has plenty of surface area.

So what would the maximum 'pee -stocking density' be?
I like the fact that there is nothing to kill with high ammonia or nitrite for short periods (the plants are very hardy (than fish) and the bacteria simply react by increasing in numbers not dying )

Is the limit simply about having enough plants to suck up nitrates?

...and enough water so that the fish are comfortable

Even if PP allowed for greater stocking levels, I would still stay below the 6kg/100l recommended maximum...provides for a far better stressless atmosphere for the fish

Where's that bloody delete button

Yeah, you are right Gokul...it would be down to if the plants could take excessively high nutrient levels

It would be at the point that the bacteria could no longer multiply enough to keep up with ammonia production, resulting in high ammonia levels, resulting in bacteria deaths, resulting in rather green water I would assume

Very hilarious
(We still respect you don't worry )

What I intend to ask is, is there any such thing as a 2:1 ratio and things like that? Could you get away with a small tank and large growbeds and keep circulating it - the idea is because it is a small tank, you could turn it over very fast with little energy requirements and help bacteria, since there is no fish involved you don't need much tank volume except for stability (temperature, spikes, etc) (But the spikes here are not scary, they don't kill any fish)

yes you could run a much higher ratio without fish gokul - pretty much would turn to hydroponics.

But its different in the view that you don't aim for sterility, and instead encourage biodiversity. (Yes, it is going to be a little boring without fish to watch)

I daresay that urea by itself would not provide all the nutrients that the plants need, you sort of need the other nutrients that are in fish food too.

i reckon a mix of urea and some sort of seasol equivalent would probably work well.

Here's a quote from wikipedia

Ok then, time for less fish, and more beer

I would say that there is a limit to how much processing a given amount of gravel can do. I never managed to get the pee ponic system to handle as much as 500 ml of urine per day. And When dosing very regularly between 200 and 400 ml per day in that system or even every other day, the Nitrates got really really high. Eventually too much nutrients can be bad for certain plants.

I would say a barrel ponic size system can operate just fine on one pee a day or perhaps even less. You are right that there doesn't need to be a minimum water level for the fish in the tank during flood of the beds though you want to make sure there is some extra for the pump to stay wet. I do have an auto top up valve installed in my barrel ponic system. As in any hydroponic system, the bigger the tank, the more stable it will be.

The way I'm figuring it, a nice humanure composting pile needs about half the family's urine to keep the composting good and hot. (Humanure composting is a really good way to save water, keep things clean/safe/sanitary, and close the nutrient cycle.)
The other half of the family's urine can be saved for ponics and/or soil garden fertilizer.

If we figure that a barrel ponics system with 60-75 gallons (227-283 L) of media in it (the two half barrels, the top bed, and perhaps any extra bagged media sitting in the flush tank and fish tank) Can grow lush and full and have nitrates too high to measure without diluting on only 200 ml of aged urine a day.

One must keep in mind that I am basing my comments mostly on my personal experience using mostly my own pee. I drink lots of water and I pee a lot so perhaps my pee is not as strong per ml but I produce more of it. Everyone else trying stuff out may get slightly different results based on different body chemistries, intake and output of fluids, and diets.

If designing a system to use all the urine from a person for a day, based on my experience, I think it would need to be at least 10 times as big if not more.
So per person, 750 gallons (2800 L) of gravel (that is bigger than my monster grow bed on the big system!) And one would need a "pish tank" for diluting and pumping of at least 500 gallons for the flood and drain.

Then lets talk about pathogens and safety. It is a good idea to seal up and age the urine to allow the urea to convert to ammonia, this brings the pH up killing off most pathogens. This is quite safe to do in small containers but in a very large containers it can be very dangerous. Also, if you are continually adding to the pee tank, how do you draw out the "aged urine" doesn't really work as things are all mixed up. To find ideas and methods on how to create a large, high tech, integrated system of these sorts, you will have to start researching the countries that are already collecting urine for use as fertilizer. I believe it is being done in Scandinavia somewhere.

I will personally stick to the lower tech methods of utilizing urine, humanure compost, and gray water since it seems that the lower tech methods come out easier and more convenient in the long run. Higher tech methods often require more stuff, parts, etc that cost and may need regular replacing or fixing. When the high tech methods fail, they are often abandoned which is wasteful and then people insist that such "green" things don't work. Though the low tech ways may mean a few minutes of effort per month from everyone involved, it is usually much less trouble overall than the days and weeks of effort per month often required from one person constantly maintaining the high tech methods. In other words, don't spend days trying to save seconds.

But that is all just my opinion and everyone is welcome to their own.

Me too. And maybe a vegetarian diet (mine - lacto-veggy) with fewer protein may have lesser nitrogenous products.
You can do it in batches - while one container ages the urine added fresh contstantly, the other one has aged urine dripping into the tank. Then after a while the containers are swapped, use 'this one' for aging and 'the other' for dripping.
Ah yes. I could probably settle for a mixture of a medium sized peeponic system and rest for humanure. (But I am so addicted to AP-like things I feel bad going back to soil-growing )
And I will not leave AP too. I like watching happy fish.

I like the name.
Now say this aloud fast:
"Chappo does not let you chuck his cherished chift pist pish tank."


(No offense intended to Chappo, just wanted a 'Ch' name )