All Discussions Tagged 'fertilizing' - Aquaponic Gardening2024-03-28T11:51:40Zhttps://aquaponicgardening.ning.com/forum/topic/listForTag?tag=fertilizing&feed=yes&xn_auth=noNutrients - too much or too little?tag:aquaponicgardening.ning.com,2012-05-27:4778851:Topic:3421382012-05-27T17:11:51.716ZMelissa Rasmussenhttps://aquaponicgardening.ning.com/profile/MelissaRasmussen
<p>Hey everybody...here's another challenge from Africa.</p>
<p>I'm running what will be an aquaponics system, though currently we're fertilizing with semi-fermented plant tea, Bioponics-style. The system is about three weeks old, and has been through its cycling, and is growing plants (happy happy lettuce!). For reasons that take lengthy explanation, it's a 7000 gallon system with about 500 square feet of growing space, raft style. When we started it, we put in 55 gallons of tea (that had…</p>
<p>Hey everybody...here's another challenge from Africa.</p>
<p>I'm running what will be an aquaponics system, though currently we're fertilizing with semi-fermented plant tea, Bioponics-style. The system is about three weeks old, and has been through its cycling, and is growing plants (happy happy lettuce!). For reasons that take lengthy explanation, it's a 7000 gallon system with about 500 square feet of growing space, raft style. When we started it, we put in 55 gallons of tea (that had ammonia levels high enough to kill tilapia that had survived utter neglect in a stagnant puddle for 6 months...in 2 hours), and things were great.</p>
<p><a target="_self" href="http://storage.ning.com/topology/rest/1.0/file/get/2656367943?profile=original"><img width="500" class="align-center" src="http://storage.ning.com/topology/rest/1.0/file/get/2656367943?profile=RESIZE_1024x1024" width="500"/></a></p>
<p>BUT... Several days ago, our zinnias, basil, strawberries, and romaine lettuce started yellowing between the veins on the new leaves. On some other plants - particularly tomatoes, cucumbers, and cantaloupe - the new leaves are lush dark green but the older leaves are yellowing and brown along the edges. (To be fair, that predated transplant to the system. They stayed in the seed pots longer than they should have.) So now I'm not sure if we have nutrient <em>deficiency</em> or nutrient <em>overdose.</em></p>
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<p>What I've been calling symptoms of nutrient deficiency – yellowing between the veins on new leaves, yellow older leaves with slightly curled, sometimes brown edges – could <i>be</i> symptoms of nutrient deficiency. Lack of nitrogen, primarily (which is the most common deficiency), but also lack of zinc or sulfur.</p>
<p><a target="_self" href="http://storage.ning.com/topology/rest/1.0/file/get/2656368332?profile=original"><img class="align-center" src="http://storage.ning.com/topology/rest/1.0/file/get/2656368332?profile=original" width="500"/></a></p>
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<p>BUT – it could also be a sign of nutrient <i>overdose.</i> They look very, similar. Multiple nutrient overdose, according to pictures I find online, gives the same signs we're seeing.</p>
<p><a target="_self" href="http://storage.ning.com/topology/rest/1.0/file/get/2656368574?profile=original"><img class="align-center" src="http://storage.ning.com/topology/rest/1.0/file/get/2656368574?profile=original" width="490"/></a></p>
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<p>The water tests are somewhat helpful. Our ammonia levels are low, nitrites almost nonexistent, and this is just as it should be when the bacteria are happily established. Our nitrate levels are variable (between 4 and 10), as they should be, with intermittent fertilizing and constant uptake. This is lower than I've seen recommended for aquaponics systems.</p>
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<p>Thing is…the water doesn't look underfertilized. It has a distinct smell, it's growing algae (dammit), it looks rich and nutritious. And there have been successful aquaponics systems (like Friendly Aquaponics) that had nutrient levels that were undetectable by measured means.</p>
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<p>So…what? Do I fertilize more, and exacerbate the nutrient burn (which could still look like deficiency)? Do I hold off, and keep the plants hungry and growing slow? Help?</p>