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Adding potassium for flowering phases in aquaponics  RSS feed

 
Lauren Magnolia
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Wondering how one might boost the'P' factor on the fishwater. ... Woodash for the Potassium hydroxide? How much?? What about micro nutrients? Are Ever they needed in aquaponics?
 
Su Ba
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I don't have much experience with aquaponics, but there is a fairly large operation about an hour from me. They relate that the only crop that has done well for them via aquaponics is lettuce and "greens". I don't know what they meant by "greens". Thus they grew no flowering crops.

I keep tilapia and mosquito fish in my large irrigation catchment tank and grow water hyacinths in it for shade. The hyacinths bloom quite readily in the tank. I don't do anything with this system other than throw a cupful of earthworms in daily plus two large fistfuls of chopped kale and/or lettuce.
 
Alex Veidel
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Location: Elgin, IL
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Lauren Magnolia wrote:Wondering how one might boost the'P' factor on the fishwater. ... Woodash for the Potassium hydroxide? How much?? What about micro nutrients? Are Ever they needed in aquaponics?


I think you mean the "K" factor, right?

Potassium hydroxide works great, but you'll likely find yourself using it for general maintenance, as using enough to dose for a potassium deficiency would skyrocket your pH levels. Most aquaponic growers find that starting with groundwater, and then keeping your pH up with calcium carbonate (or hydroxide) and potassium bicarbonate (or hydroxide) does the job.

If I'm finding that the above general maintenance method isn't providing enough potassium, I like to supplement my K levels with potassium silicate, as it adds potassium and also soluble silicone to your system, which helps strengthen your plant's cell structure and guard against powdery mildew.
 
Andrew Brock
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I have had luck with potassium sulfate. Kelp works too. In general I'd recommend chelated iron, Epsom salt, rock phosphate, and occasionally bone meal for calcium for a productive aquaponics system.
 
Lauren Magnolia
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Forgive my npk slip. Thanks for correction. I should have thought about the hydroxide pH affect. I can understand the iron and mag salt but aren't there dangerous levels of the other things for the fish we don't want to poison ourselves..

I'm looking for something to add to the system as an element of the ecosystem. I like A,ponics for the fact it works togethe as a guild... But that's why other plants aren't doing well for others I presume.

I used washed lake gravel, crushed limestone, and lava rock in my system grew outstanding bush beans maters and rooted all sorts of berries and a rose. Chamomile did fine. Basil fantastic. Etc.... So I then wonder did I get .k. From my lava rock ? Is that rock phosphate? Also... My fish ere guppies. I fed them tropical fish food. Maybe we could look at food input for fish more for nutrient output?
 
Alex Veidel
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Location: Elgin, IL
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Lauren Magnolia wrote:Forgive my npk slip. Thanks for correction. I should have thought about the hydroxide pH affect. I can understand the iron and mag salt but aren't there dangerous levels of the other things for the fish we don't want to poison ourselves..

I'm looking for something to add to the system as an element of the ecosystem. I like A,ponics for the fact it works togethe as a guild... But that's why other plants aren't doing well for others I presume.

I used washed lake gravel, crushed limestone, and lava rock in my system grew outstanding bush beans maters and rooted all sorts of berries and a rose. Chamomile did fine. Basil fantastic. Etc.... So I then wonder did I get .k. From my lava rock ? Is that rock phosphate? Also... My fish ere guppies. I fed them tropical fish food. Maybe we could look at food input for fish more for nutrient output?


I'm under the impression that if you're using potassium hydroxide to maintain your pH (which will be naturally declining over time due to the acid from the nitrification process, assuming your water's kH levels aren't too high) and feeding your fish on the regular, then you should pretty much be getting all the potassium you need.

All I'm saying is that if your plants are showing signs that they are not getting enough potassium, then don't dose extra potassium hydroxide since it will drive your pH up. Save potassium emergency measures for potassium silicate, or something similar to that.
 
Lynn Garcia
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It is quite possible to grow flowering plants in aquaponics. The key is to use wicking beds for your flowering plants. DWC and media beds are fine for the greens.  Wicking beds with soil on the top allows you to add some nutrients in the soil above the water provided you use a specific amount of water.  If you use the correct amount the water will just be absorbed by the soil and will not bleed down into your AP tanks to spike your Ph.  There are numerous pages out there to google for this info.
 
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