420 Magazine Background

Persistent Nutrient Deficiencies on Dinafem Critical Jack & Heavyweight Fruit Punch


New Member
Link to my photo gallery at the bottom!

First here is the info!

Two Plants from feminized seed
x1 Dinafem Critical Jack-50/50 Hybrid
x1 Heavyweight Seeds Fruit Punch- Sativa dominant, percentages not provided by breeder.
Three weeks vegetative stage with 18/6 light cycle

Soil Grow
5 gallon pots
FFOF with extra perlite (unmeasured), coffee grounds @ 2 cups per container, diatomaceous earth @ 1/2 cup per container
Happy Frog all purpose 5-5-5 Organic, 1/2 cup mixed in to medium at time of planting
Happy Frog Bat Guano 0-5-0 Organic, 1/4 cup mixed in to medium at time of planting

*GH CaliMagic and Epsom Salts have been used as foliar treatment, see more below

Top dressing with DE for control of fungus gnats

Lights: x2 LED panels 300w each (170 watt net draw)
lights can be found here 100x3w led grow light

Room Temp 78-80F around the clock
Relative Humidity low 40's to low 50's around the clock
C02 enrichment using decomposition bags

Water type: R/O ph'd to 6.5 using GH ph down
Soil PH: Simple Meter reading is consistently 6.6-6.8
I have not watered heavily enough to take a run-off test
Watering has been twice a week

Pests have consisted of fungus gnats so far, but they have not proliferated. Only a few adults around the pot for a couple days but I haven't seen any since top dressing with Diatomaceous Earth.

Grow room is 2x4' and about 6.5 feet tall.

This isn't my first grow, but I'm still a bit of a novice. I have had similar issues in the past during Veg but they always seem to clear themselves up. This time the problem is progressing and I'm beginning to feel a little helpless. I have studied nutrient problems pretty extensively from multiple sources and everything seems to be pointing towards Magnesium. I had considered Potassium as well but I highly doubt it. I know my ph is a little higher than ideal but it shouldn't be causing a problem with mg in and of itself.

NOTE: Until just a couple days ago the room temp for my plants was up between 86-88F and I had to rig a way to pump my A/C into the tent. Since then the above listed temps of 78-80 have been consistent.

My ladies (I call them ladies) were very happy after their initial transfer to the large pots for about the first 2 weeks. They were a lush green and they were growing happily, albeit a little slower than if I were running the lights 24/7. About a week ago I noticed the first yellow spots on the low and middle fan leaves that soon turned a light brown. Then inter-veinal yellowing which progressed to a light tan-ish color. Almost like spilling bleach on a colored t-shirt. When I felt confident that I was dealing with a Mg problem I foliar sprayed using 5ml of epsom salts in a gallon of water and at the next watering gave them 4tsp of epsom salts in the r/o water. (dosage taken from Rosenthal's Oaksterdam textbook) The problem has continued to spread upwards to newer growth. The lower leaves now have brown and crispy edges and tips and some of the middle leaves are following suit.

I like to grow MOSTLY organic, but I'm not opposed to chemical solutions. That being said I decided to use 1/2 tsp of GH CaliMagic along with a 1/2 tsp of epsom salts in a gallon of water for a foliar spray on both the top and bottom of the leaves. I did this yesterday and today.

NOTE: Now I'm seeing on two bottom growing shoots some sort of discoloration starting on the new growth. This is something I only discovered today just before I posted this. There are a few pics of this in the gallery.

So I realize that these recent solutions may take time to start showing a rebound in the plant but I would love to hear the opinions of the "Ents" of this forum to see if I am on the right track.

If some of you nice folks would look at my photos and assess my writings with some feedback I would really appreciate it!

Full gallery available by following the link:

*This post is only hypothetical and is being used for research only. All text posted is fictional and all photos are stock images with no ownership claimed or implied by me.

Fuzzy Duck

Well-Known Member
Re: Persistent Nutrient Deficiencies on Dinafem Critical Jack & Heavyweight Fruit Pun

Ye looks like Mg -magnesium def to me...

I don't think PH is a problem either, i normally use compost around that PH myself :thumb:

How ever not all strains respond the same to nutrient requirements as some are more sensitive than others !

I know biobizz do a seaweed (cold pressed) nutrient solutions which contains many trace value micro nutrients also fortified with Ca - calcium & Mg - magnesium which is classed as organic :green_heart:

Other wise you may have shop around ?
Top Bottom