Light stress is a sign of poor nutrition

[Oldguy71]

I see just about every nutrient imbalance on the farm diagnosed as lilight stress. Healthy plants don’t really get light stress. Of course when a plant is struggling with nutrient uptake turning down the light reduces nutrient demand and the plant looks better won’t grow nearly as fast or yield nearly as much. Adjusting the light does nothing to address the cause only the symptoms.

The lights in the picture are 240w LM301 H boards at 100% less than 18” away

 

[LoveGrowingIt]

Many folks who come here asking for help don't grow like what's shown in the picture. Adjusting the light is often the best and most immediate fix, and usually does no harm. Nutrient changes take time and effort and might make the situation worse. It's not that I disagree with you, though. I know that nutrients are important. So are temperature, humidity, watering practices and growing medium. That said, you're certainly welcome to help growers whose crops are in peril. I look forward to reading your advice about how to avoid light stress through better nutrition.

 

[budsofgeorgia]

Looks like cannabis to me in the picture and I thought that is what we growed here

 

[dankfrank83]

I have heard about this and how the number of light hours affect your nutrition needs. It makes sense. If I am laying on the couch or if I'm in the gym working out I too have different nutrition need.

I'm not experienced enough to have an opinion though. I am looking forwards to reading your breakdown on it and learn more about nutrition Thanks for joining

 

[Oldguy71]

Don’t get me wrong, I’m not saying raising or turning down the light won’t help. It probably will but it’s a symptom of a bigger problem not a fix. Most of the posts that have a light stress diagnosis don’t talk about the underlying issues. My only advice on proper nutrition is correct ppm/ec, use a complete fertilizer organic or mineral with the right ratios, correct ph range, good temperature and humidity control, and good watering practices are all nessary for really good plant health. But we all know that stuff. I think the biggest mistake people make is over feeding or over amending leading to nutrient lockout. Lockout causes the plant to exhibit deficiency symptoms. It’s not for lack of nutrients in the soil, adding more to address a deficiency only makes the lockout worse.

So if you’re experiencing light stress yes turn down the light, check your runoff ppm and ph. If your runoff is. 1800 but you’re only feeding 800 there’s nutrient buildup in your medium probably causing lockout. If the runoff is 300 your plants are probably underfed. Once that’s taken care of adjust your nutrient strength and start increasing light intensity. If those parameters are good think about your watering practices or the nutrient ratios your plant is actually getting especially if you’re using 10 different additives.
I’ve been growing since 93 and I have never seen a plant with just one deficiency other than calcium. It’s almost always a sign of either underfeeding or lockout and whatever deficiency you’re seeing is just the first to show. Foliar feeding can really help recovery if you’re in veg or very early flower when you’re having uptake problems.
Just my 2 cents