Yellowing on middle leaves, new growth greener (flower day 20)

Hi RIU,

My plants are suffering from an unknown problem! Looking around in this forum I suspect it might be zinc deficiency, but I can't be sure. Here is the relevant information, hopefully one of you lurking gurus can help me figure out whats going on wrong here!

Strain: Gods Gift
Medium: Botanicare Coco / Perlite inside coco pots, drain to waste, medium fed with mister nozzles every 10 minutes.
Nutrient solution: Dyna Gro Foilage Pro (3-1-2), RO water
Other additives: Great White beneficial bacteria
PPM: 700
PH: 5.8
Temp ranges: 74-85F
RH: 0% - 15%
Lighting: 1kw HPS
Days: Day 20 Flowering

One picture is of plants 20 days into flowering, the other is of the same strain in veg, showing the same symptoms. Does anybody have a clue what might be causing the problem? From my understanding Dyna Gro Foilage Pro is a complete nutrient solution, so I don't understand what might be causing the deficiencies. The only possibility I can think is that because the PH is 5.8, zinc is being locked out?

Thanks in advance everyone.

Definitely not zinc. I recommend supplementing with cal-mag. Botanicare's is good. cn

cannabineer said:

Definitely not zinc. I recommend supplementing with cal-mag. Botanicare's is good. cn

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I thought it might be calcium deficiency but I did not observe rust spots. I didn't see the green veins with yellowing leaves symptomatic of magnesium deficiency either. I will try that though because I actually do have some Cal Mag on hand

What do you know about Botanicare coco? I used it once to great success, and then later used another brand with less success so now I am switching back to it. At my local hydro store they said it is impossible to over water botanicare coco.

^^^^hmm my guess is overwatering........don't see def or toxicity issues here

PSUAGRO. said:

^^^^hmm my guess is overwatering........don't see def or toxicity issues here

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Thank you for your input Psuagro. These plants are fed in coco by 2 GPH pot misters for 15 seconds per hour (approx 1/4 gal of water per pot, per hour). The drain bucket for all 9 plants accumulates about 3 gallons every 24 hours. Does this seem like over watering?

Also I have not noticed anything else that I usually encounter with over watering (such as algae on top of the medium). Instead of using pots, these are in big CocoTek pot liners, which I was hoping would increase the aeration of the medium. As far as my attempt, it seems to be better than traditional pots so far.

**Ok I decreased the feedings about about 33%. Also attached another picture of an unusual characteristic of the leaves that might help troubleshoot




This is how the pots are watered. Check out the roots growing out of the top of the medium! Its like aeroponics but with medium, ha ha.

Quite a hybrid system you got their grower^^^....looks to be working fantastically....be safe and happy growing

After turning down the watering schedule, the plants do look a bit better. I got a closer look at one of the yellowing leaves displaying the most severe symptoms.


Anybody know what the deal with those spots are?

this is strain dependent! gods gift is know to do this no matter how much cal mag u give or fixin u try to do. it gonna do it.

I've had this several times before and answered it with giving it a dose of bat guano mixed with water. It worked for me.