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View Full Version : AP & High Phosphorus requirement plants?



wh33t
09-13-2011, 01:58 AM
Hey all,

From my understanding any plant that produces some kind of fruit (like a tomato or strawberry) usually requires higher amounts of phosphorus when planted in soil during their flowering/fruiting phase of life. I'm just curious how do these kinds of plants get their phosphorus requirements met in Aquaponics? Am I correct in understanding the primary nutrient in the AP environment is nitrogen in the form of a water soluble nitrate? If so, how do Tomatoes and other fruiting plants do so damn well in AP?

Someone told me that if I ever have problems with fruiting plants not producing fruit it's probably due to lack of phosphorus and one person even suggested using Neon Guppies or Tetras but didn't elaborate on exactly why.

Your thoughts?

stucco
09-13-2011, 02:59 AM
I think that the guppies guy was pulling your leg. I’ve had lots of success with tomatoes and flowering stuff by adding calcium supplements and doing foliar spraying with vermiplex, compost or maxicrop teas.

urbanfarmer
09-13-2011, 04:04 AM
The nutrients you MAY have trouble with are iron, potassium, and calcium in that order. Magnesium and sulfur in theory could be on the list too, but we just haven't seen much problems with those as a community. If you look at your fish food, you'll see it's high in phosphorous. It's good to think about these things because you gain a solid understanding of them. Keep asking and researching, we'll get you there! :-D

bsfman
09-13-2011, 05:49 AM
The nutrients you MAY have trouble with are iron, potassium, and calcium in that order.

Just an FYI - Black Soldier Fly larvae are high in both potassium and calcium (phosphorus too)! (And the tilapia LOVE them!) It's a win/win for both plants and fish!

Here is the dry matter content of the BSF grubs I raise (analysis done by University of Georgia Feed and Environmental Water Lab)
Phosphorus - 1.64%
Potassium - 1.90%
Calcium - 4.40%

Iron content was 732 ppm which is 732/1,000,000 or .0732%

urbanfarmer
09-13-2011, 06:45 AM
The nutrients you MAY have trouble with are iron, potassium, and calcium in that order.

Just an FYI - Black Soldier Fly larvae are high in both potassium and calcium (phosphorus too)! (And the tilapia LOVE them!) It's a win/win for both plants and fish!

Here is the dry matter content of the BSF grubs I raise (analysis done by University of Georgia Feed and Environmental Water Lab)
Phosphorus - 1.64%
Potassium - 1.90%
Calcium - 4.40%

Iron content was 732 ppm which is 732/1,000,000 or .0732%
You are just full of wonderful information aren't you?? :mrgreen:

bsfman
09-13-2011, 06:59 AM
You are just full of wonderful information aren't you?? :mrgreen:

Well, I try. Just don't seek advice from me on applying 2 part poly! (Haven't quite mastered the intricacies of that stuff yet!)

wh33t
09-13-2011, 12:09 PM
Fantastic guys! Thank you!

How can I create some kind of object to catch black soldier flies? Come to think of it, I'm not sure I've ever heard of Black Soldier flies where I live. Is there something else I could use? I'm on Vancouver Island, Bc, Canada.

urbanfarmer
09-13-2011, 01:07 PM
Fantastic guys! Thank you!

How can I create some kind of object to catch black soldier flies? Come to think of it, I'm not sure I've ever heard of Black Soldier flies where I live. Is there something else I could use? I'm on Vancouver Island, Bc, Canada.
I'm pretty sure your climate does not support BSF. However, you can try an indoor setup. You can always take them out during the warm months as well. I will let bsfman explain it better, but it takes a bit more work to do it indoors.