Hi all. Indoor hydroponic garden here. I have a few fruiting plants and I noticed that the leaves are turning yellow between the veins, but the veins are still very green. I was thinking that it might be a base nutrient deficiency. The fruits are coming along and there are perhaps another another 4-5 weeks before full maturity. I feel that the plants are stunted. Can anyone tell me how to get it healthy again? Symptoms: older leaves on top are turning yellow and have rust spots. Some of these leaves on the lower half of the plant that have been left alone are turning brown, crispy, and/or fallen off. New growth are still green but is starting to turn lighter in color, moving towards yellow. I suspect it's potassium deficiency, which in turn is locking out nitrogen. I am thinking that I should leach the medium and start with just base nutrients (N-P-K formula). Any thoughts?
The best way would be to replace the medium and nutrient solution. Leaching may help if there is an excess of salts. To run a hydro system it is usually beneficial to invest in solution monitoring equipment, at least a pH and a TDS 'pen', in order to monitor the situation, both can be had for under $100. Solution temperature, usually measured at the reservoir is also important for water quality. Many growers also use a dilute amount of hydrogen peroxide (food grade) in their solution to attempt to maintain cleanliness.
Thanks for replying. The medium I'm using is rockwool so it's impossible to switch mediums at this point. I have a PPM/PH pen to gauge everything and it's always on target, which in my case is 5.6 and around 1300-1500 ppm. I have considered testing hydrogen peroxide to see how it works, but at this moment I'm using beneficial bacteria and I'm told that hydrogen peroxide will kill everything wanted and unwanted. I was told to pay more attention to the NPK. Can you comment on that? What I heard was that the N should be high during the vegetative state through the beginning of flowering and P should be higher during mid flower until the end. Is that true?
