A Community and Forum For Aquaponic Gardeners
Need help with hydroponic questions
I love talking with hydroponic gardeners about aquaponics. They just can't believe that aquaponics works as well as we all know it does. The reaction is typically "now let me get this straight...no EC meter? No muli-part, expensive nutrients? And you never dump out the nutrients?" It is fun.
There one question that occasionally comes up that I just got from a commercial grower in Spain through LinkedIn that I can't answer very well and I'm hoping someone in this community can help me out. He asks "Do you have info you can share on the chemical composition of the fish waste? How do you adjust it to the plants' requirements? "
The second question can be handled with a simple...you don't have to, just like you wouldn't in a dirt environment, but you could do some slight tweeking of potassium, iron, phosphorus etc. if you really think you need to (I never have).
The first question, though, is knowable through lab tests...I just don't know of anyone who has done this. Do you?
Replies to This Discussion
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Permalink Reply by TCLynx on
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I think the biggest challenge here is switching from Hydroponics to Aquaponics is really a Paradigm shift and not all people make those jumps easily, quickly or even willingly.
I actually had been doing Hydroponics for a couple years before I seriously looked at Aquaponics and I didn't really come round to the aquaponics directly. I had to venture into vermiculture, permaculture and other things before I stumbled upon the BYAP Forum which was the first place I found that explained the nitrogen cycle quickly and clearly enough for me not to click away before I learned something.
The Hydroponic mindset is all about control. For Aquaponics to work, you have to let go of much of that control since you have to let an ecosystem grow in your system. You can't be sterilizing it every three to six months and you don't get to micro-manage the nutrients.
So, if a hydroponic grower wants to continue micro-managing, then leave them to their hydroponics.
If they are ready to make the shift to promoting a balance (which requires some compromise) then they could be ready for Aquaponics.
Once some one makes the shift, I doubt they will go back.
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Permalink Reply by Two Jay on
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Sylvia, I have the info you are looking for... but need to scan it or retype it. ( :
It's titled Nutrient output to water. Let me try to get to it later tonight.
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Permalink Reply by Sylvia Bernstein on
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Thank you, Two Jay! I really, really appreciate it!
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Permalink Reply by Ingo Bläser on
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Hello Sylvia,
thats a very interesting question. I found a table about the amount of the nutrients at www.asianfisheriessociety.org
Here is the link to the pdf-file of the Article "Effects of Tilapia Stocking Densities on Fish Growth and Water Quality in Tanks" http://www.google.de/url?sa=t&source=web&cd=16&ved=0CDc...
and the table
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Thanks, Ingo. Very cool information, but not quite what I"m looking for. I want an answer for hydro folks when they say "yeah, but have you looked at the nutrient profile?" We all know that plants grow great, but I'm looking to cover all bases. Thanks again.
Ingo Bläser said:Hello Sylvia,
thats a very interesting question. I found a table about the amount of the nutrients at www.asianfisheriessociety.org
Here is the link to the pdf-file of the Article "Effects of Tilapia Stocking Densities on Fish Growth and Water Quality in Tanks" http://www.google.de/url?sa=t&source=web&cd=16&ved=0CDc...
and the table
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Hum, ya might ask Nate if he has done any leaf tissue testing on any of his plants in AP. I know not quite the same as testing the water for the nutrients but perhaps even more useful.
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Problem is that it needs to be compatible to information that a serious hydro person would have readily at hand - they think in terms of what is in the nutrient bath. Leaf tissue analysis comparisons rely on using the same plant at the same age and stage as each plant uptakes differently at different times in it's life.
TCLynx said:Hum, ya might ask Nate if he has done any leaf tissue testing on any of his plants in AP. I know not quite the same as testing the water for the nutrients but perhaps even more useful.
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This is coming for a professor of Aquaculture at MSU.
His quick, basic, assessment of fish waste to the nutrient requirements of plants.
Nutrient output to water.
While some other nutrients are expelled in fish waste (fish expiration and fecal material), the 3 most focused on for plants include CO2, ammonia and phosphorus.
Feeding 1kg of fish feed produces the average:
Waste - 650g total waste (360g soluble in the water = 290g in fecal material)
CO2 - 280 - 350g CO2 is expelled in the water (soluble)
Nitrogen - 52g total nitrogen (41.6g soluble, 10.4g fecal)
...... Soluble Nitrogen - 29g is in the form of N. This converts to 1.2 x 29g = 35gTAN (NH3/NH4+)
...... (TAN = 1.2 x total N weight)
...... 13g is tied up in "other" forms
...... Fecal Nitrogen - 10.4g also mainly in "other" forms
Phosphorus - 5g total phosphorus in fecal, although this leaches into the water if solids not removed right away.
Enjoy
Two Jay said:Sylvia, I have the info you are looking for... but need to scan it or retype it. ( :
It's titled Nutrient output to water. Let me try to get to it later tonight.
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Thanks, TwoJay. Still not quite what I'm looking for - hoping to find a panel of the 16 micros and macros plants require - but this is a start.
Two Jay said:This is coming for a professor of Aquaculture at MSU.
His quick, basic, assessment of fish waste to the nutrient requirements of plants.
Nutrient output to water.
While some other nutrients are expelled in fish waste (fish expiration and fecal material), the 3 most focused on for plants include CO2, ammonia and phosphorus.
Feeding 1kg of fish feed produces the average:
Waste - 650g total waste (360g soluble in the water = 290g in fecal material)
CO2 - 280 - 350g CO2 is expelled in the water (soluble)
Nitrogen - 52g total nitrogen (41.6g soluble, 10.4g fecal)
...... Soluble Nitrogen - 29g is in the form of N. This converts to 1.2 x 29g = 35gTAN (NH3/NH4+)
...... (TAN = 1.2 x total N weight)
...... 13g is tied up in "other" forms
...... Fecal Nitrogen - 10.4g also mainly in "other" forms
Phosphorus - 5g total phosphorus in fecal, although this leaches into the water if solids not removed right away.
Enjoy
Two Jay said:Sylvia, I have the info you are looking for... but need to scan it or retype it. ( :
It's titled Nutrient output to water. Let me try to get to it later tonight.
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Sylvia, That would be a great list to see. Keep us posted eh?
Sylvia Bernstein said:Thanks, TwoJay. Still not quite what I'm looking for - hoping to find a panel of the 16 micros and macros plants require - but this is a start.
Two Jay said:This is coming for a professor of Aquaculture at MSU.
His quick, basic, assessment of fish waste to the nutrient requirements of plants.
Nutrient output to water.
While some other nutrients are expelled in fish waste (fish expiration and fecal material), the 3 most focused on for plants include CO2, ammonia and phosphorus.
Feeding 1kg of fish feed produces the average:
Waste - 650g total waste (360g soluble in the water = 290g in fecal material)
CO2 - 280 - 350g CO2 is expelled in the water (soluble)
Nitrogen - 52g total nitrogen (41.6g soluble, 10.4g fecal)
...... Soluble Nitrogen - 29g is in the form of N. This converts to 1.2 x 29g = 35gTAN (NH3/NH4+)
...... (TAN = 1.2 x total N weight)
...... 13g is tied up in "other" forms
...... Fecal Nitrogen - 10.4g also mainly in "other" forms
Phosphorus - 5g total phosphorus in fecal, although this leaches into the water if solids not removed right away.
Enjoy
Two Jay said:Sylvia, I have the info you are looking for... but need to scan it or retype it. ( :
It's titled Nutrient output to water. Let me try to get to it later tonight.
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I have a lab I used to use for AeroGrow to do this kind of thing, but the tricky part with AP is that a chemical conversion is taking place in the grow beds by the bacteria so what is in the fish tank isn't what is actually available to the plants. Hmmm....I'll have to give this more thought...
Two Jay said:Sylvia, That would be a great list to see. Keep us posted eh?
Sylvia Bernstein said:Thanks, TwoJay. Still not quite what I'm looking for - hoping to find a panel of the 16 micros and macros plants require - but this is a start.
Two Jay said:This is coming for a professor of Aquaculture at MSU.
His quick, basic, assessment of fish waste to the nutrient requirements of plants.
Nutrient output to water.
While some other nutrients are expelled in fish waste (fish expiration and fecal material), the 3 most focused on for plants include CO2, ammonia and phosphorus.
Feeding 1kg of fish feed produces the average:
Waste - 650g total waste (360g soluble in the water = 290g in fecal material)
CO2 - 280 - 350g CO2 is expelled in the water (soluble)
Nitrogen - 52g total nitrogen (41.6g soluble, 10.4g fecal)
...... Soluble Nitrogen - 29g is in the form of N. This converts to 1.2 x 29g = 35gTAN (NH3/NH4+)
...... (TAN = 1.2 x total N weight)
...... 13g is tied up in "other" forms
...... Fecal Nitrogen - 10.4g also mainly in "other" forms
Phosphorus - 5g total phosphorus in fecal, although this leaches into the water if solids not removed right away.
Enjoy
Two Jay said:Sylvia, I have the info you are looking for... but need to scan it or retype it. ( :
It's titled Nutrient output to water. Let me try to get to it later tonight.
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I tried explaining this to my visitors on Thursday, they either didn't understand, care, believe me or D all of the above .. not really sure which it was yet. ( :
Sylvia Bernstein said:I have a lab I used to use for AeroGrow to do this kind of thing, but the tricky part with AP is that a chemical conversion is taking place in the grow beds by the bacteria so what is in the fish tank isn't what is actually available to the plants. Hmmm....I'll have to give this more thought...
Two Jay said:Sylvia, That would be a great list to see. Keep us posted eh?
Sylvia Bernstein said:Thanks, TwoJay. Still not quite what I'm looking for - hoping to find a panel of the 16 micros and macros plants require - but this is a start.
Two Jay said:This is coming for a professor of Aquaculture at MSU.
His quick, basic, assessment of fish waste to the nutrient requirements of plants.
Nutrient output to water.
While some other nutrients are expelled in fish waste (fish expiration and fecal material), the 3 most focused on for plants include CO2, ammonia and phosphorus.
Feeding 1kg of fish feed produces the average:
Waste - 650g total waste (360g soluble in the water = 290g in fecal material)
CO2 - 280 - 350g CO2 is expelled in the water (soluble)
Nitrogen - 52g total nitrogen (41.6g soluble, 10.4g fecal)
...... Soluble Nitrogen - 29g is in the form of N. This converts to 1.2 x 29g = 35gTAN (NH3/NH4+)
...... (TAN = 1.2 x total N weight)
...... 13g is tied up in "other" forms
...... Fecal Nitrogen - 10.4g also mainly in "other" forms
Phosphorus - 5g total phosphorus in fecal, although this leaches into the water if solids not removed right away.
Enjoy
Two Jay said:Sylvia, I have the info you are looking for... but need to scan it or retype it. ( :
It's titled Nutrient output to water. Let me try to get to it later tonight.
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