Beginner: Possible nutrient burn/deficiency or overtemp

Hey folks, new to growing and hydroponics too. Have some questions. About 2 months into this grow cycle and have been getting a lot of yellowing/drooping in the leaves. This is widespread throughout the plants. Please take a look at these pictures and let me know what might be causing this.

Strain; White Widow

Hydroponic - rockwool cubes

System type? HPS light 600W on digital ballast; grow tent

PH of water? 6.0

What is strength of nutrient mix? 24.8.16


Light system, size? HPS 600W

Temps; Day, Night … 78-80f

Humidity; Day, Night…40%

Ventilation system; yes, fans.

AC, Humidifier, De-humidifier: AC only

Co2; Yes

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Hopefully this chart will help
-good luck

I suggest getting Fox Farms Sledgehammer and flushing the pots with it. Follow up with more ventilation in case heat is aggravating the situation even more…

…how much air do you have in the water?

…what is your PPM?


The above chart suggests a potassium deficiency

Looks like an overload on nitrogen, and a deficiency on calcium and magnesium, also potassium and possibly phosphorous, also hydro your ph should be 5.3-5.8, and yes I agree with @Paranorman, what is your ppm?

I’d flush with Epsom salt 1/4-1/2 tsp per gallon then I’d give something with a N-P-K ratio along with CaMg

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Sorry I missed the hydro thing but the need for you to flush out the excess Nitrogen remains. 24-8-16 is pretty strong medicine. I’m at 5-3-5 unless they are really hungry.

This is a good situation to try an experiment. There are products out that contain silicone which is the most common element on earth but usually missing in hydro or peat grows. It gives the plant strength and resistance to stresses like heat, lack of humidity and too much nutes. I mix ½ tsp per gallon every watering, but I’m in a soil mix. You need to check if it will chelate in your hydro system. If it reacts with your liquid nutes, it will lock up, form a sand like a substance and may mess up your pumps and emitters. But if it doesn’t, it’s like spinach for Popeye and you will quickly see the difference.

Potassium helps and makes it more tolerant to stress levels

831ppm. Measured with a digital meter. I thought that the nutes might be overloaded. I will flush the system immediately and back off on the fertilizer. Just wanted to say that you guys are incredibly helpful and responsive. Already loving this community.

Welcome to ilgm, please keep us updated with your progress

I would say heat stress plus low humidity I would try to get a temp gun reading of leaf surface my nute levels are 40-20-60 plus 25 ml/g of high brix molasses 0-0-3 I give this ten days after transplanting clone no ill effects I get my numbers by number on bottle times ml

Really? A heat gun thermometer? Isn’t this complicated and expensive enough? Lol. I’ve used a $10 Taylor humidity Guage and a $20 max/min thermometer in my grows for twenty years.
Maybe Bluetooth and upc codes next?

Temp guns are 10$ off ebay and well worth it

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I’m with ya Charles I don’t have one either but if I lower my t5 my temp gauge in canopy still stays at 77 because of fans but I can see plant start to stress out

I’m also in soil forgot your hydro only 2nd pic looks like nitro tox other 3 look like heat stress the way the tips curl

What brand temp gun do you have?

ebay is the best, many models for $10-$20 and up depending on needs.

I’ll get the link and post it for you brother I’ll be right back

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For the money, one of the better $10-$20 buys.

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Yea definitely this link should work

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I like these temp guns I have one in my shop and i have one at home for the grow rooms, works great for finding overheating part of car and make sure plant canopy is at a good temperature

Bought…now the waiting starts…interesting mail soon…castings, guano, temp gun…