Hydroponic Nutrients and Developing An Eye for Major Nutrient Deficiencies:
Over the years in growing, I´ve certainly developed a good eye and honed my "Spidey Senses" (Yes, I´m also a Marvel Comics geek) for being able to spot the tiniest of things going on with my crop and affecting the health of my little ladies.
Each nutrient your plants take in has a direct effect on a certain area of the plants´ growth and overall health. I wanted to take a minute to share some of the quick observational keys I´ve learned over time to help you guys out there, particularly those growers who have decided to go it on their own by mixing their own hydroponic nutrient mixtures for solutions. I´ll address that topic more directly under a more detailed article, but suffice it to say, you enter into a risky area when you leave the path of working with a pre-made, trusted baseline fertilizer and nutrient additive combo. Let's break things down, per major nutrient. For simplicity´s sake, we will follow the traditional, N-P-K breakdown:
Nitrogen (N): Have you noticed your plants being a little short and stunted looking? Are you seeing yellow or pale-ish green color overall? These are some tell-tale signs that if you have mixed your own nutrient solution, you aren´t putting in quite enough Nitrogen. Up your nitrogen content by around 25% and see how the plant behaves from there
Phosphorus (P): If your plants are continually coming up stunted but overly green in appearance then they are not getting enough phosphorus absorbtion. This situation can be trick though, because another factor may be at play here, so the first thing you will want to check is the overall temperature around the crop. If your ladies are too cold, this will limit there phosphorus intake. I recommend upping your temperature a little and see how that goes first before adjusting up the P concentration.
Potassium (K): The main "Yellowing Factor" - If you notice severe yellowing with brown or black spots on leaves and in particular, severe yellowing with leaves obviously drying and curling up, this is a clear indicator that you have to significantly increase your K concentration.