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Help! Hydroponic tomato deficiency

Posted by jamesvlad (My Page) on
Wed, Aug 18, 10 at 14:21

Hello everyone. I have a hydroponic tomato, but it seems to have a deficiency that I cant identify...maybe someone can help me.

The nutrient solution composition is:
N 181
P 51
K 267
Ca 123
Mg 42
S 42
using tap water (about 40 ppm of calcium) phosphoric acid as phosphorus source, and some sulfuric acid to adjust pH.

and micronutrients (Fe, Cu , Zn, B, Mo, Mn) but Im not sure about the concentrations

This is the picture


Follow-Up Postings:

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RE: Help! Hydroponic tomato deficiency

Sorry!!

This is the link of the picture:

http://www.flickr.com/photos/25020806@N08/4904706243/


By the way...do you know how to insert images in this forum?

Thanks in advance!


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RE: Help! Hydroponic tomato deficiency

What is the picture? I see no picture.

I assume your N is NO3?

Note that things other than deficiencies can cause problems. Last year I had a problem with tom survival, and after a lot of experimentation, I determined that it was a phytotoxic reaction to the insecticidal soap I was spraying.


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RE: Help! Hydroponic tomato deficiency (2)

Ah, I see you fixed it. You add images with <img src="http://YOUR_URL">


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RE: Help! Hydroponic tomato deficiency

Thank you karenkei. Yes my N is NO3 only (Ca(NO3)2, KNO3 and NaNO3, HNO3). I use only the nutrient solution, no more things.

This is the image:


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RE: Help! Hydroponic tomato deficiency

Hello Jamesvlad,

I once had similarly looking plants when doing some experiments with hydrogen carbonate ion concentrations. If you can indeed provide all your 51 ppm of P as phosphoric acid and then you need to add sulfuric acid on top of that to reach a pH around 5.5-6.5 then the problem might be an excess amount of carbonate in your water.

The lack of any chlorosis suggests that there are no micro nutrient or N deficiencies but the leaf deformation and the similar appearance when compared with my experiment plus your description makes me believe that this is the problem. I would suggest you prepare your solution with RO or distilled water from now on and share your results with us once you do this.

I hope this helps !

Best Regards,

Daniel


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RE: Help! Hydroponic tomato deficiency

Thank you danielfp. Again, youre right. The hydrogen carbonate concentrations is high. Ive been using distilled water, and the toxicity is disappearing. The leaf are returning to normal, Im going to take another photo and insert the picture in two or three days.


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RE: Help! Hydroponic tomato deficiency

10 days ago I changed the nutrient solution (without bicarbonate), I now this is the result:

As you can see, the tomato is returning to normal.

So, for anyone who may have the same problem: the excess of bicarbonate ion could be the problem.

Thanks again danielfp and karenkei.


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