Possible toxicity

[Felipe Cohen]

Hello everyone,

I'm setting my first aquaponic system. I have some experience in aquarium and aquaculture, but when the subject is plants for food I have a big lack of knowledge. I know that plants absorb Nitrates and Ammonia, so, is there any possibility of plants getting toxic for absorbing to much ammonia? How about cyanotoxins? Keeping my pond in the shadow is enough to prevent cyanobateria growing?

I have plenty of questions but first I’d like to discuss about the possibility of growing some toxic veggies. I’m looking forward to hear your experiences about this.

My best regards,

Felipe

[Jonathan Kadish NYC AA Chair]

Cyanobateria need to photosynthesize so simply shading your fish tank from sunlight solves this issue. The good bacteria are Nitrosomonas: bacteria that convert ammonia into nitrites, and Nitrobacter: bacteria that convert nitrites into nitrates. This is what happens in soil and in solution. They use the ammonia/nitrites in place of photosynthesis for their energy source.

 

[Felipe Cohen]

Hey Jonathan thanks for replying!!  When you say shading dosen't mean cover it at all does it? I don't want to cover the tank because I'm afraid to have problems with the oxigen. I know that the bacterias will transform ammonia in nitrates, but I was concerned about producing too much ammonia and the plants that are close to the inflow would abosb it before transformation. Is it to crazy think this way?

[RupertofOZ]

Young plants during seedling stage take up ammonium directly through the roots... but once leaf growth begins... plant growth is primarily via nitrate transportation to the leaves... and photosynthesis...

 

Once your system is cycled... you shouldn't be recording any significant ammonia levels... the nitrification of your system should be converting any ammonia inputs to nitrates almost immediately... before they reach any "toxicity" levels that might harm the plants...

 

And any such potential toxicity levels that might harm the plants... would have killed your fish way before the plants...

[Jonathan Kadish NYC AA Chair]

Well your fish will die if your ammonia levels or nitrites are too high. Fish are much more sensitive then plants to it.

[Felipe Cohen]

Thank you Jonathan and RuertofOZ, I'll keep monitoring ammonia levels :-)