first hrow major leaf problems

Hi all,
I have 3 White Crystal plants 5 weeks old from seed. The problem started 2 weeks into the grow and steadly got worse.
The first 4 weeks of their life was spent in 70% peat 30% perlite. Watered when needed under the same light, thats all.
Last week I changed to hydroponics as I thought they were not getting the correct nutes using soil.
Now it has been in the new system for a week and the problems are still getting worse, so it can't be the nutes??
I had another 5 plants from seed ready to grow too so I put them all in the together a week ago and today I see those early signs on their leaves too.
Details at the moment..
PH 6
CANNA aqua vega A&B 20ml per 10 liters in a hydroponic micro jet system spraying the roots for 15 minutes every 1 hour with an air stone on constant in the water.
250 watt HPS a foot and a half away from the top of the plants on 18/6 hour light cycle.
The grow space is in the actic closed in by foil covered isulation board with an opening at the top where the light shines down through. the light its self is outside the space.
I have no fans or extractors but the door of the grow room is left open for 10 hours a night to the actic space.
Tempreture, light on, around 27 degrees light off 10 degrees.
The first 3 plants are 6 inches high and the 5 others are 3 inches
Hydrolica clay pebbles medium.
As you will see from the pics. 1 plant has yellow bottom leaves, turning brown and dying. the other big plants have brown spots getting bigger, turning black drying to a crisp and dying. The 5 amall week old plants have just started to have the same tiny brown spots showing.
All help please.
Thanks again

Should get rid of that tin foil on the bottom its not doing anything good for the plant other than overheating it.

Get side lights, reflecting light for the bottom leaves isn't needed

I could be wrong, but switching from Soil medium to hydro at 4 weeks is probably going to Shock and stress the shit out of any plant.

also from 27 (80F) to 10 Degrees (50F) I think is a HUGE drop for the plant to be put under, this plant just seems to be constantly put under a lot of stress.. You should try and work on creating a more stable environment for your babies

Nute burn maybe? Or maybe a serious magnesium deficiency.. But im shootin for nute burn.
That foils not good to have in your grow space. It has very little reflective qualities and creates hot spots. All its gonna do is eat up your light and burn up your plants.

Thanks for the replys guys. I'll get rid of the tin foil, I was just using it to stop light getting into the tank and the medium. What should I have as my walls, just white paint? sorry the degrees was supposed to be 27 high and 20 low. I don't think it's nute burn as they were showing these problems when they were in soil with no extra nutrients added. I forgot to mention that I have 1 plant still in the original soil/ lerlite mix and it also had the same growing leaf issues. I had thought that is could be mag deficiency but would the Canna not have enough of that in it already? I then thought of, heat or air flow or moisture, its only effecting the lower leaves. Any other thoughts?

this may help... how is your nutrient plan?



Major Elements


Nitrogen (N) – a major element needed by all green plants. It is transported from older growth to new growth. Deficiency – lack of lush green color, especially in older leaves. Toxicity – soft, dark green leaves, long weak stems, poor root development and slow to maturation.

Phosphorus (P) – an important mineral that stores energy in plants and animals, also a flowering agent. Deficiency – stunted, dark green leaves. Lower leaves turn yellow and die. Leaves have brown or purple spots. Toxicity – small, curled new leaves. Early maturity, large root systems.

Potassium (K) – a nitrogen catalyst needed for enzyme manufacture. Needed in large quantities, although plants do not use a tremendous amount. Deficiency – brown, necrotic (dead) tips and edge margins on older (lower) leaves followed by yellowing of the entire leaf. Dead brown spots on older leaves. Slender, weak stems and small seeds. Toxicity – saline condition, marginal leaf burn, wilting and drying due to poor water uptake.

Calcium (Ca) – helps form the structural parts of the plants (it is a major element in cell walls). Counters acidity (low pH). Deficiency – new growth affected first. Root tips turn brown and die. Hard, stiff new leaves with dead edges and brown spots. Stems are stunted and woody, blossoms fall off. Little or no fruit. Toxicity – rare, but can cause an alkaline (high pH) condition, wilting, iron and potassium lockup and deficiencies. Calcium is not very mobile in plants.

Magnesium (Mg) – is important in photosynthesis and the chlorophyll molecule where light energy is converted to chemical energy. Chlorophyll gives plants their green color. Deficiency – chlorosis (yellowing) of older leaves between the veins. Later, leaf tips curl, entire plant turns yellow and dies. Magnesium is mobile and is transported from older to newer growth. Old growth is affected first.
Toxicity – edges curl on leaves, small stems, signs of potassium deficiency.

Sulfur (S) – is a building block of amino acids and proteins. Used in small amounts, it aids transpiration and transport of other elements. Deficiency – rare, but young leaves turn pale green with yellowing along the veins, stems turn hard and woody. Plants are stunted and spindly. Toxicity – saline condition, wilting.

Iron (Fe) – is an important constituent of enzymes and plays a role in photosynthesis. Iron is not very mobile in plants and can be "locked up" if the pH goes much above 7. Deficiency – yellow or white chlorosis between veins of younger leaves. Stunted new growth with spindly stems. Flowers drop off before opening. Toxicity – deficiencies of other elements, brown spots on leaves.

Minor Elements


Manganese (Mn) – plays an important role in photosynthesis and chloroplast membrane formation. Needed at only ½ the rate of iron, its importance cannot be understated. Manganese also enters into the chemical reactions of oxidation and reduction. Deficiency – dead (necrotic) spots on younger leaves. Hard and woody stems, slow maturity. It is not very mobile in plants, so younger growth usually exhibits symptoms first. Toxicity – wilting and death in all but small quantities. Note: manganese is toxic in large amounts.

Boron (B) – is needed in small amounts. Boron aids in cell division and in transporting sugars through cell walls. It also aids in forming the amino acids – thymine and cytosine, important to DNA synthesis. Deficiency – affects new growth first. Black, brittle areas on leaf tips. Small, burned leaves with dead spots. Stubby brown and dead root tips. "Heart rot" in beets and "stem crack" in celery. Toxicity – above 10 PPM, dead leaf margins, wilting and quick death of the plant.

Copper (Cu) – is needed in only small amounts. This metal aids in plant metabolism and general health. It helps ward off disease and pests, aids in the utilization of iron and the manufacture of enzymes. Deficiency – dark green, spindly young leaves. Plants are susceptible to disease and insects, wilt easily and exhibit stunted growth. Toxicity – dark roots, leads to an iron deficiency (interveinal chlorosis on young leaves).

Zinc (Zn) – is needed in small amounts for growth and chlorophyll synthesis. Deficiency – short stem internodes and a condition called "little leaf" or "rosetting" where the young leaves are spindly and twist around each other. Reduced or no bud formation. Mottled dead spots between veins. Toxicity – related to an acid pH, splotchy mottled leaves and wilting.

Chlorine (Cl) – this element controls water uptake and transpiration. Stimulates photosynthesis and is a major constituent of the anthocyanin molecule. Deficiency – plants wilt easily. Bronze colored leaves with dead or chlorotic spots, stunted roots with club-shaped tips. Toxicity – saline poisoning, small dark leaves, burned margins and wilting.

Molybdenum (Mo) – a catalyst needed in small quantities. It is involved in nitrogen fixation (assimilation) and in the manufacture of enzymes. Deficiency – causes nitrogen deficiency. Plants are light green, malformed and stunted. Causes the "whiptail" disease where young leaves are long, narrow and severely twisted, but not tightly bunched as in "rosetting" caused by zinc deficiency. Toxicity – very toxic to plants above 100 to 200 parts per billion (not much!). Causes iron and copper lockup and improper nitrogen utilization.

Cobalt (Co) – a constituent of vitamin B-12 and required for the fixation of nitrogen and DNA synthesis. Deficiency – causes pernicious anemia (lack of vitamin B-12) and improper nitrogen assimilation. Toxicity – all but the smallest amount causes quick wilt and death.

Good post Hiro.

Hey man I think I am having a similar problem. Your pics are a little fuzzy but did it start out like this? (first pic)
https://www.rollitup.org/marijuana-plant-problems/325007-what-these-brown-dots.html

They are about 2 weeks old. I'm growing in soil and haven't used any nutes yet. I think I might need to transplant them into bigger pots maybe. I'm guessing it is some kind of deficiency. I watered them today with 1/4 strength Schultz 10-15-10 since it's all I have and my Botanicare didn't arrive yet. Hopefully it helps. Did you notice if your stem was turning red/purple? This is outdoor grow that I'm starting indoor. I think I might try to get them outside this week into some real soil and some real sun.

Hi guys,
Thanks for the replys. I posted some new pics above on my last post, see what you think hopefully they have better quality for ya.
1st got rid of the tinfoil, then made a cling film hood and put it over all of them last night as I thought the moisture level was low, I also cut off the bad leaves. This evening the next set of leaves are turning black but the the leaves are not dryed to a crisp like before so maybe the moisture was one of my problems.Also of the 5 newer plants, which are growing rapidly, I show 2 of them in the new pics as very green and healty with no problems at all and another in the exact same conditions showing the eame early problems as the larger one's. I think this is very strange????
Sonar my stems are a little purple and yes they did start as tiny brown dots anywhere on the leaves and always the bottom leaves first.
Hiro thanks for such a detailed list, it's excellent. I have no plan Im afraid I am using CANNA aqua vega A&B as directed on the bottle 20ml per 10 liters. Would the plants be lacking in anything even if they ware on CANNA nutes. they are as follows
NPK 6-3-8
Ph today is 5.9
I see reading your post, 1 of my plants must have had Phosphous def as it had yellow lower leaves and a large root system compared to its 2 counter parts. I am still not sure about the ones with the leaves turning brown and black???
Is Canna Aqua vega giving my babies enough of what they need??? or should I increase the nute ratio or add something to increase the amount of some specific elements???.
Thanks for the help guys, please don't give up me and my babies.
What do I use to raise Phospours??

like I said I don't know anything about hydro, but if you think your phosphorous is low, use a nute with more of it. if the stuff you are using now is NPK 6-3-8 you might want something with a higher middle number IF that is actually the problem.

Have you ever seen this? Don't know how reliable it is, but I've seen it floating around
https://www.rollitup.org/attachments/general-marijuana-growing/395557d1198364479-charts-charts-more-charts-nutrient_chart.gif

hi guys, i said id let you know how my leaf problems turned out. my babies are doing great now. I left the cling film hood over them and lowered them to 20 inches away from the light. I think the major issue was humidity levels were too low. I still have an odd leaf with spots but the majority of them are perfect. I just want to thank all who replyed to my thread.