Found some interesting recipes and/or info on the various N-P-K values of some common organic compounds. What do you use for inputs for your fish-less systems?
"Instructions for Preparing Organic Fertilizers
Organic fertilizers need not be expensive and can be made on your own. This recipe,
to the best of my knowledge, was created by Steve Solomon, founder of Territorial
Seed Company. All measurements are shown in terms of volume, not weight.
4 parts seed meal
1 part dolomite lime
1/2 part bone meal or 1 part soft rock phosphate
1/2 part kelp meal
1. Seed meal provides N and smaller amounts of P and K. Some states prohibit its use
in certified organic operations (not something a home grower needs to be
concerned about). Other options are afalfa meal, or rape/canola meal. The NPK
value of cottonseed meal is about 6-2-1. Bloodmeal can be substituted in place of
some seed meal, since it acts more quickly. Use three parts seed meal and one part
bloodmeal. Seed meals tend to be acidic, so lime is included to balance that.
Dolomite limestone is roughly half magnesium carbonate (MgCO3) and half calcium
carbonate (CaCO3). Calcitic limestone is pure calcium carbonate. Plants usually
need more Ca than Mg, therefore a mix of 2/3 dolomite lime and 1/3 calcitic lime
2. Bone meal and rock phosphate provide the bulk of the P component. Less bone
meal (NPK 0-10-0) is required since it releases its P more readily. The advantage of
using rock phosphate (NPK 0-3-0) is that it continues to contribute P to the soil over
many years. Bone meal is produced as a byproduct of the beef industry while rock
phosphate is mined.
3. Kelp meal (NPK 0-0-10) contributes K and micronutrients. It tends to be more
expensive than the other components. Another possible K source is Jersey
greensand. It has the same advantages and liabilities as rock phosphate (very slow
release) but does not supply micronutrients. Wood Ash is also a plentiful, viable source of K.
Formulas for Balanced, All-Purpose Organic Fertilizer, Fertilizer Ratio
Fertilizer Ratio (N-P2O5-K2O) Ingredients:
2-3.5-2.5 -1 part bone meal
3 parts alfalfa hay
2 parts greensand
2.5-2.5-4 - 3 parts granite dust
1 part dried blood
1 part bone meal
5 parts seaweed
4-5-4 - 2 parts dried blood
l part phosphate rock
4 parts wood ashes
3.5-5.5-3.5 - 2 parts cotton seed meal
1 part colloidal phosphate
2 parts granite dust
0-5-4 - 1 part phosphate rock
3 parts greensand
2 parts wood ashes
2-8-3 - 3 parts greensand
2 parts seaweed
1 part dried blood
2 parts phosphate rock
Substance Nutrient: Elements Supplied:
Blood meal 15% N, l.3% P, 0.7% K
Dried blood 12% N, 3.0% P, 0% K
Bone meal 3.0% N, 20.0% P, 0% K, 24 to 30% Ca
Cottonseed meal 6% N, 2 to 30% P, 2% K
Fish emulsion, fish meal 10% N, 4 to 6% P, 1% K
Hoof and horn meal 14% N, 2% P, 0% K
Leatherdust, leather meal 5.5 to 22% N, 0% P, 0% K
Kelp meal, liquid seaweed 1% N, 0% P, 12% K
Calcite, calcitic limestone 95 to 100% calcium carbonate
Colloidal phosphate or soft
omission 0% N, 18 to 20% P, 27% Ca, 1.7% iron phosphate, silicas, 14 other trace elements
51% calcium carbonate, 40% magnesium carbonate
Granite dust, granite meal,
crushed granite minerals 0% N, 0% P, 3 to 5% K, 67% silica, 19 trace
Greensand, glauconite 0% N, 10% P, 5 to 7% K, 50% silica, 18 to 20% iron
oxide, 22 trace minerals
Gypsum (calcium sulfate) 23 to 57% C, 17.7% S
Langbeinite 0% N, 0% P, 22% K, 22% S, 11% Mg
Rock phosphate 0% N, 22% P, 0% K, 30% Ca, 2.8% Fe, 10% silica, 10
other trace minerals
Sulfur 100% S
Composted cow manure 2% N, 1% P, 1% K
Guano (bat) 8% N, 40% P, 29% K average, but varies widely, 24 trace
Guano (bird) 13% N, 8% P, 20% K, 11 trace minerals
Rabbit 2.4%N, 1.4%P, 0.6%K
If you want to use organic nutrients in "hydroponic" growing, you need to allow those nutrients to be converted by microbes so you want to treat it more as bio-ponics (don't go sterilizing your system between each crop or you won't have the microbes in good supply to turn your organic fertilizer into plant food and you would wind up with a nasty goop soup.)
In a seasoned Aquaponics system suddenly devoid of fish (and not planning to see fish again) one could easily mix up some of these mixes and expect the worms/microbes to turn them into plant food.
In a fresh new system that hasn't cycled up, it will take some time for the nutrients to be mineralized for the plants.
TC is right, you still (mostly) need to rely on the microbes to break the elements down into their plant usable ionic form. Sterilization and even drastic pH adjustments seem to effect the way these systems work in a negative way. Probably very similar to how they would impact an AP system that relies on its bio-filter to make nutrients plant available.
And I wouldn't feel right advocating anyone be adding anything straight into an AP system that they care about. These recipes are more for fish-less systems, or small experimental AP systems for those that don't mind potentially killing some fish in the name of tinkering...Though there may, in certain circumstances be ways to dose certain plants with particular nutrients, without potentially effecting the entire system...The whole idea behind the dual root zone thing...
People probably have their own ways of doing these things, some relatively simple, some more complex. I hope to learn what/how others are doing similar things.
It helps to know the nutrient requirements of your cultivars. Different salads and greens I've had success with just tossing a small handful of worm castings in a sock and putting that in an aerated reservoir...some rusty nail filings and what was already in my well water...At the moment I'm trying out (a half-baked 2 part "formula" of mine) worm tea mixed with wood ash and hummonia and trace elements. First i treat my well water with HCL to get it down to a decent pH (this process also releases plant usable Ca2+ from the calcium carbonate in the water. There is also Mg already in that same water, and some copper and iron from contact with the pipes. The portion with worm tea and wood ash I do not pH adjust)...
If I understand what you guys are saying, you can't add the organic fertilizer in the system because the bacteria need to transform it before it's usable by the plants and by the time that happens it would hurt the fishes... So could it possible to have a small fish-less and may be even plant-less system on the side, mostly media and a water circulation and aeration system where you could put your fertilizer, let the microbes do the conversion/break down to the ionic form, then, after proper testing, take some of this water and put in the system that has the fishes to fertilize it ? The same amount of water would be taken out of the fish-system first and put back in the fish-less "fertilizer-processing" system for another enrichment round... Basically it would be like having a system that makes an AP fertilizer in the form of nutrient rich AP water. Or is it that even after break down in the fish-less fertilizer breakdown system this water would still be harmful to the fishes ? What am I missing ?
Peter, what I do, I term hydro-organics, a type of bio-ponics. In my system, I now connect my raised, wicking, grow beds to my pond. Since my beds are soil based and top dressed with compost, I have a limited top watering schedule, mainly to activate the microbial populations rather than to water roots. I would do a Tea drench every two weeks to flush and enrich microbial activities.
Please read my blog for more info (if interested).
@ Alexandre I'm guessing that many people have an 'excess of fertilizer' in their overstocked AP systems. Depending on the quality of your fish food an AP system once balanced, mature, and running at a nice low pH, is more than likely sufficient in providing all plant nutrients. New systems may not be (again all of this is very dependent on situation). A new system that was cycled with hummonia is already better of than one cycled with pure ammonia, especially in the generally notoriously low K department. But, yes you may be able to 'pre-process' some nutes if you felt that you needed to. I would however most likely stay away from things like the recipes listed above as I feel that would be an undue amount of P for a system with fish, and you could potentially be inviting problems. Instead of a 'general formula' you could target specific nutrients that are deficient in your particular system. Or even target specific plants without contaminating your AP system with fertilizer. As far as what exactly would be harmful to the fish directly (other than metals or nitrites) I don't really know. I'm hoping some of the aquaculture people could shed some light on the matter. Within reason, I'm thinking that even those nutes would be ok, but don't really know.
@ John, Thanks. In all honesty, I didn't really think this kind of thing would generate much interest at all :)
And the numbers you provided are very interesting, the bat guano NPK is mind boggling ! Probably because of the high protein insects diet they have ... I've got THOUSANDS of giant 2 feet wing span bats flying over the house every day at dusk on their way to their feeding ground. I wish I knew where they nest, there must be tons of this nutrient bomb waiting to be shoveled up :)
Also I read in a permaculture book that its possible to get them to nest in a shelter you build for them if it's done in a way that suits their requirements, but I'm somehow a bit doubtful it would work that easily... That would be a boon for any compost pile.
Holy cow, those are some big bats! I bet you're right, they drop a lot of nice nugs. You'd probably have to wear scuba gear just to breathe in there hehe...
IDK, it might work, but I remember seeing in some documentary a HUGE structure that was built for that purpose and the bats just pretty much ignored it for years (decades even I think).
has anyone tried a system using just worm tea? If you can grow in just worm castings, why wouldnt you be able to use just worm tea in a hydro system?
Hey my reply didn't post!
Yes, I'm sure that other people out there have done just that. I ran a small system with just worm tea this past summer/fall. Worked fine. pH tends to be a bit high, and things looked better when I added a Maxi-crop type product (if I lived by the sea I'd just add a bit of sea water for micro-elements). A couple grams of rusty nails helped too i think. Right now, I'm finding that worm tea, a little maxi-crop, and a small amount of hummonia and a tiny bit of wood-ash, works real well. (I'm trying to figure out why the hummonia seems to stabilize the pH. Also, having at least a little bit of nitrites seems to help with ionic uptake of other elements...and since there are no fish, this is not a problem...
Well the humonia acts as an ammonia source and the nitrogen cycle has an acidifying effect so if you found that the worm tea alone was raising your pH then adding ammonia that has to be converted by the nitrogen cycle will help counteract that. Of course the whole balance will be affected by the source water and what you feed the worms along with everything else.
At first I thought that the 'fancy' pH meter that I bought was 'on the blink' so I double checked with the Tetra test, the water was a bit discoloured, but seemed to jive with the pH meter reading. Started to calibrate the pH meter, and found I didn't have too. Whatever combination of things...it's working out so far. More dumb luck than anything else, I had added the bit of hummonia for a totally different reason, but am more than happy with the freaky-stable pH results.
Your probably right, the little bit of hummonia and the nitrification process is more acidifying than all that worm tea and nitrates. The worms eat all sorts of vegetable/fruit scraps with rotten banana peels being the main course. Finely ground eggshells (mortar and pestle then screened through a 'fine' mesh was also added to the bin to help get the them into a 'sexy-time' pH range (probably aiding with the high pH of the tea?)
I don't adjust the teas pH with acid,(or the water I use for the tea before hand) as I don't want to affect the bacteria or possibly the nitrates in some way. (Once I added acid to lower a jar of waters pH after I had already added Fe chelates...the water went from being a nice red to a rather light pink real fast? Wonder what's up with that?
At any rate I appreciate any ideas you have on the matter.