Calcium Magnesium Deficiency?

Hi guys I am new to the forum and desperately seeking some help with an issue the just appeared this morning. I was using a viraspectra 900 watt LED in my veg tent and recently moved my plants to my flower tent with 4x QB288 boards 3000 K with Cree 660 add on at 480 watts. The plants dried out quickly so I feed two days in a row with remo nutrients and this morning they look like this?

Calcium Defientcy?

No picture attached

pict4 pict3 pict2 pict5

Additional Information regarding Flower Tent Setup

4xQB 288 with Cree 660 add on LEDs
4x8 Mars Hydro Tent
Saturn 6 Controller
C02 tank pumping 1200 ppm into tent
Humidity between 65 - 70 percent
Temp 26 Celsius
Dehumidifier Frigidaire
6 " Exhaust Fan with Mountainair Carbon Filter
Portable Air Conditioner Vented outdoors

Another Picture from the top

Pictures of entire plants …pict7 pict8

Anyone ?? I am getting really worried and have no idea what to do. Any help would be really appreciated!

PH 6.0
Still on Vege but moved into flower tent with different lighting?

Thanks guys…


Welcome to the forum @mmouncey

Here is some pics to reference relating to CalMag issues.
I’m still trying to get a better grasp of reading the leaves and decide what they are telling me as it seems many different issues are similar in appearance to one another.

To me it looks like it could be a CalMag deficiency but again I’m not there yet to say definitively.
Just remember it didn’t happen overnight so correction will also take time.
pictures of calcium magnesium deficiencies in cannabis plant below

@garrigan62 @dbrn32 @MattyBear … maybe one of these gents can chime in with their thoughts

Hope this helps and HAGD


Well first the change in lighting might be some of it. But you’ve got a bit of nute burn and based on the color they’re definitely over fed. You might want to do a water next time they’re dry rather than feed twice in a row. Also a calmag supplement would help with the higher powered lighting they will need it.

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Welcome to the forum!

I see you’re at 6.0ph, which makes me wonder what you’re using for medium? Sorry if you posted and I missed it. Also wondering if you’ve been measuring ppm in/out?

Separate non related question for you, what are you using from cree for the 660nm? Do you have any pics?

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Good catch on the ph I missed that.

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Calcium (Ca) -Macro Nutrient and an Immobile element.


Calcium is another important element that helps the plants cell walls,
cell division in
making the plants stems, stalks, branches stronger, as well as
contributing to root growth,
mostly the newer root hairs, Calcium also helps enhancing the
uptake of K in the the plants
roots. Calcium moves really slow within the plant and tends to
concentrate in roots and older

When plants exhibit a Calcium deficiency the younger leaves are
the first to show it as well
as older leaves. The Leaf tips will die back, the tips may curl,
and growth of the plant is
stunted. The plant can show a weakness in the stems and branches,
as well as a under developed
root system that can lead to bacteria problems with roots dieing off.
Having slow plant
transpiration rates can aggravate the uptake of calcium. Make sure your
soil isn’t very acidic,
for calcium gets harder to be absorbed through acidic soils, Which leads
to having a plant that
is deficient in Calcium. The leaf tips, edges and new growth will or may
turn a yellow/brown color
that happen in spots and often surrounded by a sharp brown outlined edge
and then the leaf tips die
back. If too much calcium is given at an early stage of growth it can
stunt the growth of your plants.
Having to much of calcium will also flocculate when a concentrated form
is combined with potassium.
The parts affected by a calcium deficiency are the roots. Stem or petiole,
young or old leaves.

Too much Calcium will lead to other micronutrient deficiencies. Calcium
fixation is caused by many
types of mediums such as: clay soils, unbuffered coco and humus. The lime
tends to bond to these
soils very easily. The stems of the plant will not be able to hold the plant
up and will exhibit
a white brown in between the veins of the leaves when having too much calcium.
Also having to much
potassium and or nitrogen will cause a calcium lockout.

Problems with Calcium being locked out by PH troubles

Very acidic soils with excessive potassium, dry and or wet soil.
Lack of calcium in the soil may
cause too acidic soil. This may cause to Mg or Iron deficiency or
very slow stunted growth


Calcium gets locked out of soil growing at ph levels of 2.0- 6.4
Calcium is absorbed best in soil at a ph level of 6.5-9.1 (Wouldn’t
recommend having a ph of over 7.0 in soil)
anything out of the ranges listed will contribute to a
Calcium Deficiency.

Hydro and Soil less Mediums

Calcium gets locked out of Hydro and Soil less Mediums at ph levels
of 2.0- 5.3
Calcium is absorbed best in Hydro and Soil less Mediums at ph levels
of 5.4-5.8 (Wouldn’t recommend having a
ph over 6.5 in hydro and soil less mediums.) Best range for hydro and
soil less mediums is 5.0 to 6.0.
Anything out of the ranges listed will contribute to a Calcium Deficiency.

Solution to fixing a Calcium deficiency
To fix a calcium deficiency you can treat by foliar feeding with one
teaspoon of dolomite lime or
Garden lime per quart of water, Or Any Chemical/Organic nutrients that have
Calcium in them will
fix a Calcium deficiency. (Only mixing at ½ strength when using chemical nutrients
or it will cause
nutrient burn!)
Or you can take crushed up dolomite lime or garden lime in a gallon of water
and water it in the soil.
1 to 2 teaspoons per gallon of water, which will be slow acting. Garden Gypsum,
which is medium absorption.
Limestone, which is medium absorption, Rock Phosphate and Animal wastes which
are both medium/slow absorption.
Note: Caution when using gypsum to an already acid soil (pH that is less
than 5.5) can have a very bad effect
on different types of plants by effecting the absorption of soil aluminum,
which is poison to plant roots.

Now if you added to much chemical nutrients and or organics, (which is hard
to burn your plants when using organics)
you need to flush the soil with plain water. You need to use 2 times as much
water as the size of the pot, for
example: If you have a 5 gallon pot and need to flush it, you need to use 10
gallons of water to rinse out the
soil good enough to get rid of excessive nutrients.


Thanks for your response! Sorry for the late reply but because I am new to the forum it wouldn’t let me till this morning. This is a picture of the 4x Quantum 288 Board with the Cree upgradeQuantum Cree


I recognize those lol.

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Thank you for the responses everyone and sorry I could not reply until today due to forum rules. Anyways I am growing in soil (ProMix) and using reverse osmosis water. Last night I went out and bought a PPM meter. I filled a 10 gallon bucket with strait tap water (Well) brought the PH down to 6.0 with a PH down solution and tested the PPM it was at 620. I ran 2 liters of the water thru a plant and re tested the PH was at 6.3 and the PPMS were way up at 2400 so I continued to rinse until the PPMS got down to 720 about 100 over the strait water. I was told to let them sit now for 3 days then start feeding again with half the recommend dose. Using remo nutrients line that does have CalMag included…pict77 best pict77 pict78 pitc79 test

Can anyone recommend the PH level I should be at and what PPMs I should be seeing after a proper feed with REMO nutrients? One of the replys above states calcium will be locked out of soil below a PH level of 6.5?


You’re not really in soil. Promix recommends 5.8-6.2, I would stay in that range. I suspect that flush will help, hang around the 6.0 with the proper ppm level and keep monitoring your runoff and plant conditions. If ph wants to start trending up you start dropping your ph in a little.


Thank you !

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How early would you recommend using CalMag?

Depends on your situation. But for me I start it around 2 weeks old and run all the way to the end. But it varies from plant to plant on needs. Also growing medium (soil, hydro etc.) Plays a part and so does lighting.

There is too much which can cause an excess. But if you follow the instructions usually you won’t have that problem. Most discontinue use in flower. But that’s dependent on the things above.