Iron Deficiency Color Chart

Hey everyone, hope the community here finds this deficiency chart useful. I wrote a guide about how to fix an iron deficiency in cannabis, along with this chart and pictures.

The biggest problem of iron deficiency is that it can be tricky to identify. Growers often confuse the lack of iron to other deficiencies such as magnesium, zinc, or nitrogen.

Yet iron deficiency signs and symptoms are quite unique.

First, upper leaves will begin to lose color starting at the base of the leaf .

Then, newborn leaves will turn completely yellow or almost white due to the lack of chlorophyll.

On a late stage new shoots will be damaged and growth will slow down .

Iron deficiency spreads slow. So you have plenty of time to make the right diagnosis and provide the remedy.

But, if you let this continue leaves will turn completely white and shoots will be so damaged that they will no longer grow.

If you happen to be going through an iron deficiency, the answer is most likely in the roots. As iron is usually present in tap water and growing mediums.

First check your pH to see if you’re allowing for the absorption of iron . Excess salts or nutrients (especially phosphorus) can also lead to a blockage of iron.

Any situation that messes with the root systems, such a stress, cold, over water, bad drainage, can cause an iron deficiency.

If none applies, or maybe you’re using reverse osmosis or distilled water, you may need to add iron.

Fear not, cal-mag and other commonly used supplements come with a good amount of iron, so you can fix it promptly.


I also ran across this when using water conditioners to remove chlorine. The conditioner also removed heavy metals. It was remedied with cal-mag foliar spray and discontinued use of the water conditioner.

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Did the green return after the remedy?

Yeah, this was her a few days later

Then a few weeks later


She looks so healthy :heart_eyes:

Great to know you were able to help her recover.

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She was a good plant. She gave up 8oz dried and cured. But I learned my lesson with those aquarium water conditioners.


So to be clear for anyone reading, your problem was that reverse osmosis was removing minerals from the water? Thus leading to a lack of iron?

No, it was the use of a water conditioner that I used to remove chlorine. When reading the fine print I noticed it also removed heavy metals.


Not cool, man. :guitar::metal:

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Gotcha. Thanks for the info, it’s great to know

If you don’t mind me asking what kind of ratio did you use for the foliar spray and how would I apply it if I’m on a 24/7 light schedule. My plants are getting really bad. Any help would be greatly appreciated. This is the cal mag solution I have.