I am setting up a system after so much research. I will start tomorrow. Before i decided to start, i really researched a lot on the nutrients. I would not setup a system i could not maintain. I am in an agricultural country we have tons of fertilizers available, it seems though that hydrops require unique nutrition and from the fora i have been to, soil based fertz are really not advisable. You mentioned that you keep tropical fish, do you think i can use the aquarium water for my system. I am from the philippines and i keep 3 LARGE aquaria of tropical fishes.
Also i am considering the philippine "guano" we have plenty of supply here. One of the major islands in the philippines is "infested" with bats.
advise please...

Bricks,
Nothing wrong with aquarium water. Have used that myself. Only trouble is knowing the concentration of its constituents. And test kits can be expensive.

As for bat manure . . . my suggestion is to throw a handful in a tub with (old) aquarium water. It is wise to add a few tablespoons of chlorine(bleach) in order to sterilize the mixture. Leave it overnight and then put in some airstones to drive off the chlorine.
Next, adjust the pH to just below 6.5 with some very diluted phosphoric acid, battery acid (=sulphuric acid) or vinegar(if you have neither), and fit an aquarium biofilter to break down ammonia and nitrite.
You must check the pH, as it will go down over the next few days. DonÂt let it go below 5.5. Adjust it with fresh woodash, ½ a teaspoon at the time. DonÂt let the pH go too high though. Stay below 6.8 otherwise the nitrification process will stop.

You might want to invest in an EC-meter. Check ppm. If below 800 add a bit more bat manure. If more than 1300, dilute with aquarium water. Adjust pH to ±6.3.

Switch off filter and airstones and allow the "soup" to settle. Siphon off the clear liquid the next day, and hey . . . . . youÂve got yourself some very acceptable hydro nutrient.

Would you believe that IÂve done this with dog manure? I gave it up because it was a bit of a mission, and my wife started to make serious objections. But I did have some success with it.

By-the-way: The best woodash for this purpose is made from hedge clippings (young shoots) TheyÂre loaded with potassium. Let them dry first, then burn them to make ash.

Of course, your circumstances may be different, but the above procedure gives the general idea. Make the necessary adjustments based on results, and . . .
Have fun

Regards
Greystoke

Some tips,

Don't load the system with too much manure. Little bits at the time might take longer, but its sure to give better results.
Instead of chlorine to sterilise, you can boil the manure (that's the part my wife didn't like!) but it works well.

thanks greystroke

now am ready. (except with boiling the manure).

i'll post the results on this thread. My lettuce seedlings are germinating can't wait to transfer them to my new system (70% done)...

Hum, heck using the biofilter would probably make diluted urine into an acceptable nutrient. I wonder if this is how somebody will finally manage an organic hydroponic nutrient.
Interesting,

Urine is the wonder nutrient. The Swedes have done a lot of research on it. You must dilute it at least 10x.
Downside is that it is deficient in calcium & magnesium. You add that in the form of woodash as a "pH=up" powder.

Agricultural characterisation of human urine:
Total nitrogen 2500.00 mg/L
Ammonium 2200.00 mg/L
Potassium 1200.00 mg/L
Total phosphorous 170.00 mg/L
Sulphur 130.00 mg/L
Magnesium 0.82 mg/L
Copper 0.30 mg/L
Manganese 5.20 µg/L

tclynx,

I can give you a recipe for urine nutrient if you're interested.
Used it once, but never got around to test it.

My understanding is that the nutrient and ph content of urine will vary widely from person to person as well as over time in one person. Diet and personal metabolism will affect all this.

In any case the nutrient content in one person's yearly urine is said to be enough to grow enough grain for that person for a year. I'm not sure how accurate this info is. I expect that perhaps with proper permaculture techniques and soil growing, it could probably be enough to grow all the food for one person.

Anyway, I would be interested in your urine nutrient formula.

I used a 100L plastic drum with a 20L plastic bucket perched on top. The bucket was filled with "bioballs", and the bottom was punctured full of holes.
I used a fairly large (45Watt) marine pump in the big drum to pump the water in the top bucket (biofilter). The system was seeded with a handfull of garden soil.

Next, I added 6L of urine (took me a week).
Check the pH daily. Keep it around 6.5! Use vinegar or woodash, depending. Soon, the pH will start going down regularly. Use woodash to correct.
The nutrient is ready when the system stabilises.
(This is the point where my wife threatened divorce if I used the stuff on her veggies! )
Because the nutrient will be deficient in Mg and P, you must add ±30g Epsom salt and ±15g mono potassium phosphate (KH2PO4). Final adjust pH to your prefered value.
If you can measure ppm, it should be somewhere around 1300 - 1500.

Good Luck

greystroke,
Cool thanks. I know a little about pond biofilter systems and pond building it sounds cool.

epsom salt is easy but I'm not sure where/how to look for mono potassium phosphate? Any suggestions?

Finally, which ppm scale are you quoting from? There are two which is why I prefer either EC or CF to avoid the confusion.

I don't know how likely I am to try this out soon but it is an interesting idea that I will keep in mind.

Instead of "bioballs" (which are expensive) you can use clay bricks chopped into 1-2' pieces.
I got mono potassium phosphate from my chemist. Alternatively you can use a similar amount of triple super phosphate 75% soluble, but then make sure your woodash contains enough potassium. (burn hedge clippings!)
EC values should be ±1800µS

A pity you can't edit messages. So now I'll go down mixing inches and feet!
I meant: "clay bricks chopped into 1-2 inch pieces"

When I made the biofilter for the pond, I used a bag of lava rocks since they are light and have plenty of surface area and crevices for bacteria to form on.

grestoke,
Can you tell us more about your hydroponics with worm tea? I set up a worm farm not too long ago. I know some people make use of the leachate from a worm bin and call it worm tea but others will say the leachate is worthless and that to make worm tea you must soak worm castings in water. I'm not sure what I think of either comment yet. I need to test out how well the liquid that collects in the bucket works to know if it is worth much.

How are you planning to use the nutrients from the compost for hydroponics? Making compost tea?

Bought the worm tea from a nursery. So, I don't know how genuine this tea was. It may have been spiked for all I know. Anyway, got to trust people sometimes, I can't keep worms. Too many ants.
Typical worm tea contains ±2%N, 2%P and 1%K. I poured the tea (750mL) in a 10L bucket and added a teaspoon of epsom salt. I fed this to my 8 chard plants who consumed it inside 3 weeks without any adverse effects.

I intend to build a compost bin on top of a 200L tank. I'll keep this tank filled with tapwater using a ball valve. Every night a timer activates a pump to give the compost a shower. The leachate returns to the tank.
The compost will be "spiked" with bonemeal and dolomite. Don't know how much yet. Will depend on results.
I can measure EC, pH, nitrate and hardness. Am looking for a phosphate kit.
Can't wait to get cracking. This will be so interesting. Unfortunately, some drunk fool drove into my garden wall. So, right now, I'm laying bricks.

while i'm very++ new to hydroponics - at this point I'm just trying to soak it all in, no pun intended - I do know a little bit about brewing compost tea...

Leachate != Compost Tea. it's still contains a lot of good nutrients, but it is not the miracle substance I've come to know as compost tea... The main reason is because the leachate doesn't contain the same high numbers of *living* beneficial microbes (various fungi and aerobic bacteria) in it as an actual, brewed compost tea would.

Also, I wouldn't recommend using chlorinated tap-water for this process either as the chlorine would kill these microbes. You can dechlorinate the water by letting it set in the sun for a day or so - or better yet, collecting it from rain-barrels, although I don't know how practical that is for most set-ups.

When I brew compost tea I use large air-stones as bubblers on the bottom of my bucket to keep the water highly oxygenated to keep those microbes alive and the whole process takes about 24-48 hours.

I will say though, in a hydroponics system you should be able to keep the tea "alive" for quite some time because I'm learning that most reservoirs include bubblers to keep the water oxygenated, otherwise, the tea "dies" about 4-6 hours after the bubblers are turned off in the brewer.

---
<shrug>

Don't know if any of that helps...

Here is a link that might be useful: GardenWeb's Compost Tea FAQ

Very interesting!

Thanks for reminding me about the chlorine. I keep tropical fish, so I know the dangers. I always filter the water through activated charcoal, which removes most of the chlorine. IÂll fit an in-line filter.
I hadnÂt planned on using bubblers. They make a lot of noise, but after reading your post I will  at least  make provision for aeration. Another plan that might work would be to install a small aquarium pump (Greystoke

I agree about compost tea being better brewed from finished compost rather than trying to get enough leaching through an active compost pile. The reasoning, wetting a compost pile that much will likely create several problems.
How much do you know about composting?
Here are a couple links that can teach a lot about composting even if you are not composting the topic of the book.
http://www.jenkinspublishing.com/humanure.html
http://www.weblife.org/humanure/default.html

Active compost should be only as wet as a wrung out sponge. Any wetter and you can develop anarobic conditions which can kill many of your desired microbes and cause very stinky odors.

If you have access to some good finished compost (or do the composting yourself to create it but composting takes time) then spike it as you were planning and put it in a fabric sack and soak in water with a bubbler to brew your own compost tea.

Let us know how it goes!!!

Hi greystoke,
I read your article about using urine to feed your plants. I would like to have your recepe of using Human urine in growing plants hydroponically.

Just because you can do something, doesnt mean you should. Using urine for plant food is one of those things. Unless you eat the same foods everyday, at the same times, and have the same level of activity your urine will be different with each "dose". Unless your extremly broke and have no other means of feeding your plants, I see no useful reason to even try it. Especially if you dont eat well. I'd expext the only people that would have real benificial urine would be extreme vegans. The fats and other preservative found in all our food these days isnt all that healthy for us to eat, let alone to "recycle" them just to end up eating them again.

Hi safwat,
You can find my "recipe" a few posts up in this thread, but remember that I never actually tried it. Meanwhile a friend of mine advocates to dilute the urine first about 4X with ordinary tapwater, then bottle it and let it stand for a few weeks to allow the urea to hydrolyse completely into ammonia. After that you add it to the biofilter at a rate of ±1L/day.

Hi darthhelmut,
I would agree with you if you live in North America or Europe. But in Africa and parts of Asia this is regarded as an interesting and promising development.
Also, the variability of the urine is not much of a problem. When collected on a daily basis, the characteristics tend to average out over time, and if you can measure EC it is possible to compensate for some of the variability.
Check out "urine" on Google and read the articles published by the Swedes.

Regards
Greystoke

Actually urine makes a great soil fertilizer. The mentality that our urine isn't good enough to recycle because of what we eat is kinda crazy. If what you are eating is so bad that the urine you make from it is going to cause your plants to become too toxic to eat? Wouldn't you be dead already?

That aside. I'm personally not sure it is worth the trouble to create hydroponic nutrient from urine but it has been working quite well for the soil plants. We collect urine for several days. A bit of vinegar in the jug helps with the odor. Then we put one cup of urine per one gallon of water and use it as a liquid fert. Sure it smells a little during the mixing and the watering but it doesn't linger the way fish oil sprays do.

By the way darthhelmut, what do you think happens to the urine you flush away? If you have well water and a septic system, it is simply getting back to the ground water and we only hope it is filtered and diluted enough by then not to pose any major health risks. If you pump your sewage to a treatment facility, they try and kill off any pahtogens with stuff like chlorine (which is pretty toxic stuff to the environment as well as us) and then if you are lucky they run it through something like a constructed wetland to try and remove some of the nitrates and stuff. Otherwise it may simply get pumped back into the water supplies where things like alge blooms and fish kills happen. If there is an emergency (like heavy rain that the treatment plant can't handle) they simply pump the stuff out where ever they usually pump it but untreated.

It strikes me as better to use it wisely rather than throwing it away (which the environment has to cope with) and then using a chemical alternative that often hurts the environment as well.