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Do I have a Cal/Mag deficiency?

CBDbudz

New Member
Hey there. I have a plant that is showing some sort of deficiency or multiple problems and I am thinking it might mainly be a calcium magnesium deficiency. Most of my plants have symptoms but one is effected much worst than the rest. All plants are being vegged. They are about 3 months old and have been having symptoms of a deficiency for a while now. I haven't made a calendar for the feeding schedule which was stupid i know, and the soil i transplanted them into was not amended. I fed them solely Fox Farm's Grow Big for a month or a month and a half since they germinated. since then I have switched the nutrients to the Advanced Nutrients with the base nutes as MicroGrowBloom and B-52 and Botanicare's Cal Mag. For the first two initial nutrient dressings of the Advanced nutes and Botanicare Cal Mag I also added Advcanced Nutrient's Voodoo juice. The I have been mixing 2 tablespoons of the each of the trio parts of the Micro Grow Bloom nutrients to 4 gallons of water, 1 tablespoon of the B-52, and when I fed them voodoo juice I put one tablespoon to 4 gallons of water as well. I put 4 teaspoons of Cal Mag per 4 gallons of water. The water I have fed them has always been super cold hose water that I used, and its about 50 ppm before anything is added. Since I never made a proper feeding chart schedule for them I have probably fed them anywhere from every 6-9 days and the soil has always been bone dry. I water quickly and full saturation of the pots doesn't really happen before the runoff comes out. Pots are five gal industrial buckets i got from home depot. I've used the General Hydroponics PH Up and Down and the green testing solution with the pipette and tiny beaker for testing the ph and its been around 5.5 to 6.5 i think. The problem has been yellowing and brown spots on the lowest growth at first and now the top leafs are starting to get yellow in places and some brown rust spots. The stems have turned somewhat purple. The Advcanced Nutrients don't rely on PH to be absorbed by the plants so i am thinking the problem is either underfeeding, nutrient build up in the soil or a cal mag problem. Thank you for taking the time to read this and i would really appreciate anyones feedback. Ill post a few pics I took of the worst plant.
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fanleaf

Well-Known Member
Well, you are only feeding them half strength of the recommended. I would stop mixing stuff up so much. The advanced nutrient line will do amazing every time on its own. I have grown exclusively with it for the last few years. I would suggest putting your pH pen out of sight. With Advanced Nutrients it will pH itself where it needs to be. Their nutrients are chelated so don't worry about the pH. It will hold steady as needed. According to the Nutrient calculator you need to be feeding 4 tablespoons of each grow, micro and bloom. 2 tablespoons of B-52 to 4 gallons of water. Leave the Voodoo Juice out at this point. That is only
for week 1 and 2 of veg. You are well beyond that. To your 4 gallons of water I would not add any more than 1 - 2 tablespoons of your calmag.
I'm not sure what you are using for light but I would make sure that they are getting plenty down into the canopy. With such a long veg time on your plants it's pretty common for the lowest leaves to start dying off simply because they're not receiving the amount of light needed down there.
Since your plants are 12 weeks old I would go ahead and go with the full strength nutrients as mentioned above. I don't know what your temperatures and humidity are at but that could be a slight Factor as well.
 
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Mr. Krip

Grow Journalist
420 Staff
OK, so technically, there's no such thing as a "Cal/Mag" deficiency. They are two different types of deficiencies (Calcium and/or Magnesium) and it just so happens that, if the cause of either of those deficiencies is NOT due to PH or other factors, a solution is to add a supplement called "Cal/Mag".

Yellowing of the plant from the bottom-up is usually a sign of a Nitrogen deficiency and you may just need to up the PPM's. It is normal for the plant to start shedding its lower leaves, but your girl is looking a little yellow at the bottom.

It looks like you may also have an iron deficiency which looks similar to a magnesium deficiency. Both show yellowing between the leaf veins while the veins stay primarily green (called "intervenal chlorosis"). The difference is that magnesium is a "mobile" element so the new grow "steals" it from the old growth. Meaning, a magensium deficiency will show in the older growth. Iron is immobile so will show in the newer growth. It does look like it's the newer growth that has the intervenal cholorisis, so I would guess iron.

What is your water source and are you measuring PH? Most deficiencies are due to incorrect PH. If you're using R/O or distilled water, you should be using a Cal/Mag supplement regularly since the R/O & distillation processes strip those minerals out. The Cal/Mag does have iron, too. However, all the Cal-Mag in the world won't help the plant if it's unable to uptake the nutes because the PH is off.

I'd start by upping the PPM's and see what happens from there!

I hope that helps! :goodluck:
 

fanleaf

Well-Known Member
OK, so technically, there's no such thing as a "Cal/Mag" deficiency. They are two different types of deficiencies (Calcium and/or Magnesium) and it just so happens that, if the cause of either of those deficiencies is NOT due to PH or other factors, a solution is to add a supplement called "Cal/Mag".

Yellowing of the plant from the bottom-up is usually a sign of a Nitrogen deficiency and you may just need to up the PPM's. It is normal for the plant to start shedding its lower leaves, but your girl is looking a little yellow at the bottom.

It looks like you may also have an iron deficiency which looks similar to a magnesium deficiency. Both show yellowing between the leaf veins while the veins stay primarily green (called "intervenal chlorosis"). The difference is that magnesium is a "mobile" element so the new grow "steals" it from the old growth. Meaning, a magensium deficiency will show in the older growth. Iron is immobile so will show in the newer growth. It does look like it's the newer growth that has the intervenal cholorisis, so I would guess iron.

What is your water source and are you measuring PH? Most deficiencies are due to incorrect PH. If you're using R/O or distilled water, you should be using a Cal/Mag supplement regularly since the R/O & distillation processes strip those minerals out. The Cal/Mag does have iron, too. However, all the Cal-Mag in the world won't help the plant if it's unable to uptake the nutes because the PH is off.

I'd start by upping the PPM's and see what happens from there!

I hope that helps! :goodluck:
I agree with you 100%. As long as he's using decent water and he ups the feeding from half strength to full strength I bet those deficiencies disappear.
 

CBDbudz

New Member
Really great info, thanks:Namaste:. I thought that a tablespoon was 30 ml lol, now it makes since. I ordered some Advance nutrient cal mag even though i might not need it if its just a malnutrition problem. I tested the PPM on my water and it was 50 which is pretty low i think. PH of the water is around 6.5 or 7, and i ph it to make it more acidic but measuring it has been a problem. The water i use is tap. Its been around 6.5 to 5.5 randomly each watering when i add PH down. Im curious what sort of nutrients are in tap water that i might need to get to boost my water's PPM if need be?
 

fanleaf

Well-Known Member
Really great info, thanks:Namaste:. I thought that a tablespoon was 30 ml lol, now it makes since. I ordered some Advance nutrient cal mag even though i might not need it if its just a malnutrition problem. I tested the PPM on my water and it was 50 which is pretty low i think. PH of the water is around 6.5 or 7, and i ph it to make it more acidic but measuring it has been a problem. The water i use is tap. Its been around 6.5 to 5.5 randomly each watering when i add PH down. Im curious what sort of nutrients are in tap water that i might need to get to boost my water's PPM if need be?
Honestly, it only 50 PPM you don't need to worry about anything other than dosing your Advanced Nutrients correctly. It will totally handle the pH for you. I've been growing with it for years and I can tell you as long as you're using the advanced nutrients you might as well just put your pH pen away and never pay attention to it. To answer your question though most water contains calcium magnesium iron and a whole bunch of other minerals but the two biggest are usually calcium and magnesium. Again though, you're using advanced nutrients so don't worry about the ph and don't worry about what's in your water so much. I know you will do great!
 

CBDbudz

New Member
Also, the temps have been good during the daytime, but im not there at night and so it might get cold. Ventilation isnt good But i have a 6 inch hurricane fan which ill put in soon. My lights are leds, the ones that have all colors. they are very bright. 500w or 600w of true wattage for the leds.
 

CBDbudz

New Member
The lights have been on 24/7 just because there are windows that make the room where my grow is cold at night but they haven't gotten below 58 i'm sure and that's good to know.
 

fanleaf

Well-Known Member
The lights have been on 24/7 just because there are windows that make the room where my grow is cold at night but they haven't gotten below 58 i'm sure and that's good to know.
Lots cheaper and better for the plants if you have a dark cycle. A small heater when the lights go off just to keep a respectable night temp is all that's needed. Just cover any small lights or LEDs on any heater covered with tape.
 

CBDbudz

New Member
Im gonna seal off the outer room from the tents with black plastic sheets to enclose the heat and a 500w fan heater with a build in thermostat would be nice, if its not too costly to run:headbanger:
 

Hdinkleman

Well-Known Member
Hey there. I have a plant that is showing some sort of deficiency or multiple problems and I am thinking it might mainly be a calcium magnesium deficiency. Most of my plants have symptoms but one is effected much worst than the rest. All plants are being vegged. They are about 3 months old and have been having symptoms of a deficiency for a while now. I haven't made a calendar for the feeding schedule which was stupid i know, and the soil i transplanted them into was not amended. I fed them solely Fox Farm's Grow Big for a month or a month and a half since they germinated. since then I have switched the nutrients to the Advanced Nutrients with the base nutes as MicroGrowBloom and B-52 and Botanicare's Cal Mag. For the first two initial nutrient dressings of the Advanced nutes and Botanicare Cal Mag I also added Advcanced Nutrient's Voodoo juice. The I have been mixing 2 tablespoons of the each of the trio parts of the Micro Grow Bloom nutrients to 4 gallons of water, 1 tablespoon of the B-52, and when I fed them voodoo juice I put one tablespoon to 4 gallons of water as well. I put 4 teaspoons of Cal Mag per 4 gallons of water. The water I have fed them has always been super cold hose water that I used, and its about 50 ppm before anything is added. Since I never made a proper feeding chart schedule for them I have probably fed them anywhere from every 6-9 days and the soil has always been bone dry. I water quickly and full saturation of the pots doesn't really happen before the runoff comes out. Pots are five gal industrial buckets i got from home depot. I've used the General Hydroponics PH Up and Down and the green testing solution with the pipette and tiny beaker for testing the ph and its been around 5.5 to 6.5 i think. The problem has been yellowing and brown spots on the lowest growth at first and now the top leafs are starting to get yellow in places and some brown rust spots. The stems have turned somewhat purple. The Advcanced Nutrients don't rely on PH to be absorbed by the plants so i am thinking the problem is either underfeeding, nutrient build up in the soil or a cal mag problem. Thank you for taking the time to read this and i would really appreciate anyones feedback. Ill post a few pics I took of the worst plant.
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i didnt read any further posts yet but soil is usually 6-7, so if you are using the drops to check ph you ahould be trying to get the ph to 6.5 (yellow) rather than eyeing it at 5.5-6. ?
 

CBDbudz

New Member
It's been about 6.5 steadily, but these last few feedings its been more 7. I'll be sticking to advanced nutes and see what yield they can produce. I don't have the cash for a nice Digital PH meter atm.
 
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