Mag deficiency?

Strain: Delicious Seeds Cheese Candy Auto
Day: 56, research says this plant should end between day 65-75.
Feeding: Water every two days, FF Big Bloom & Tiger Bloom at 30% strength every other watering. Oily Cann at 30% every 5-6 waterings.
Soil: FFOF & 20% perlite.
pH: Everything going into the plant has a pH between 6.4-6.6.

Title says it all... I have two main Colas on this plant and one of them seems to be having this issue.

Both colas... notice the one on the left


Cola in question and close-ups

phosphorus toxicity. you don't need the bloom ferts. you probably should just use one or the other and chances are you really don't need either one because that soil has fert in it already. I'd stop the ferts and the oily cann because it builds up in the soil.

Lets go on the safe side and take it you have 3 weeks left of flower, the growing period where you pack on mass, the buds swell and start to wreak of oily sweet resin! The heart rate monitor for this plant is looking slightly low in my opinion, it needs sorting ASAP. I ask myself this question...

• Is my soil/substrate carrying too much too little NPK/Salts/Ph only one way to find out...

I know people will say its bullshit but believe me it is the best way of understanding what your dealing with here.
It will take you 10 minutes to read the notes on soil growing and its problems, lots of good quality generic information. This test was used by several other growers recently, 2 of them sent me PM's...

User 1: hey man thanx for the tip dude my test was totally different to my run out check! it was ph7.3 and ppm off the scale somewhere in the 1700ppm mark. it was 10-20 gallons of ph water per 5g pot with no feed before it came down) will it stay or go back?

User 2: AAAAAAAAAAAAAARRRRRRRRRGGGGHHHHHHHHH! EC is like low at .7 so why is it I am over feeding like they all saying? PH lelvel is ok its 6.5 it must be underfeeding not over? man im confused more after doing that soil tets whats to do? Im gonna feed it fuck it

The 1st guy who followed my tip says his bud were nearly double in size after 7 days but if you can't be arsed just flush the fuck out of it running to waste and leave to drain off a day or two before just watering plain ph'd water until its showing signs of nice new growth.

2nd man who got told flush because its over fertilised, turns out he had a form of root disease/virus, coupled with fungus nats, treated it with the appropriate solution and fed less ppm but more often and got the result!

Heres the link I sent them... http://www.canna-uk.com/infopapers plus you can also look at a few good examples of deficiencies here by simply searching the nutrient name in the box. Any questions just ask me as I do this test on 2-3 soil grows around here every week, its simple

polishpollack said:

phosphorus toxicity. you don't need the bloom ferts. you probably should just use one or the other and chances are you really don't need either one because that soil has fert in it already. I'd stop the ferts and the oily cann because it builds up in the soil.

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Makes complete sense, thank you.

I will take a look, thanks Clarksville. Looks like some good information.

I don't see a soil test on that webpage. Maybe I'm missing it here, but all I see is advertising for a trip to Amsterdam, articles about pumpkins, canna brick, parsnips, and cannazym. It's mostly advertising. So the test info is where?

Seems like the effected area is closer to the center of the light. What type of light are you using? Distance? Although P is abused beyond belief among cannabis growers, I doubt P tox is your Main problem.

Alexander Supertramp said:

Seems like the effected area is closer to the center of the light. What type of light are you using? Distance? Although P is abused beyond belief among cannabis growers, I doubt P tox is your Main problem.

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I had read similarly that P toxicity is rarely a problem and started pumping it up with Cha Ching from FF, hence why P toxicity made sense (yes, I neglected to mention in OP).

This plant is about 12" below a continuous spectrum LED.

https://platinumgrowlights.com/products/p150

running autos is your first problem

and thats alot of ferts. you didnt mention if its ro water or tap. regardless, you should be in flush mode now

Velvet Elvis said:

running autos is your first problem

and thats alot of ferts. you didnt mention if its ro water or tap. regardless, you should be in flush mode now

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Tap, 150ish ppm.

Yes, next plant will be photoperiod. I am on a very tight schedule for my first grow, decided to do autos to simplify things; in retrospect, if I knew then what I know now, I could have gotten away with a normal (feminized) plant.

You've discovered why that product is called Cha Ching. It's because every time somebody wastes their money on it, the people at Foxfarm say "cha ching!"
Like a license to steal baby. If they make soil that good enough, that's all you need.

http://www.growweedeasy.com/sites/growweedeasy.com/files/phosphorus-info-marijuana.jpg

I have a reasonable answer to my problem, that's all that matters. Next grow is a single plant, 2'x2.5' - maybe I can force feed some P into that one.

staygreener said:

http://www.growweedeasy.com/sites/growweedeasy.com/files/phosphorus-info-marijuana.jpg

I have a reasonable answer to my problem, that's all that matters. Next grow is a single plant, 2'x2.5' - maybe I can force feed some P into that one.

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The full dose of nutrients for the chaching is probably based on a larger plant. Some guys grow one plant under a 1k bulb. The standard in growing is a 1k bulb. So manufacturers like to post what a full sized plant under a thousand should be consuming. Well your growing autos so you may have a smaller plant and a lower dose needed to fulfill the plants needs. Whoever said flush the plant im on board with. Then feed at 1/4 strength or less every few waters, for the rest of the grow. Theres probably lots of food still in the soil even after a flush.

Last time i had an issue like that was from p-tox. Locked a bunch of other shit out in the proccess, tops were light green with red/purple/orange blotches and mild chlorosis

polishpollack said:

I don't see a soil test on that webpage. Maybe I'm missing it here, but all I see is advertising for a trip to Amsterdam, articles about pumpkins, canna brick, parsnips, and cannazym. It's mostly advertising. So the test info is where?

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You just smoke too much shit PP... or you're getting some dodgy ad tracker fucking with your browser? Its good reading this particular article and the site in general even if you dont use their products. I personally trust Canna implicitly and don't find paying £29.95 for a 5 litre A/B combo that offensive, but theres a few products I shy away from... like plant derived magic potions!
Heres the soil growers info paper as a PDF file

staygreener said:

Makes complete sense, thank you.

I will take a look, thanks Clarksville. Looks like some good information.

Click to expand...

It is and a its a very good unbiased site for advice on deficiencies etc. If the links wrong as Polish Pollacks is saying I apologise but uploaded a PDF in my last post anyway. ATB man

Cl@rksville said:

...Heres the link I sent them... http://www.canna-uk.com/infopapers plus you can also look at a few good examples of deficiencies here by simply searching the nutrient name in the box. Any questions just ask me as I do this test on 2-3 soil grows around here every week, its simple

Click to expand...

Great site mate. Thanks for posting! I think I just figured out why my last few problems happened after reading that (first coco grow here). Possibly another rearing its ugly head. An invaluable resource for sure. Thanks again!

Did anyone notice this from here: http://www.canna-uk.com/problem_solving_coco

"If the water used to mix the nutrients is very soft, the concentration of nutrients will need to be higher or the coco will rob the nutrients and calcium deficiency will begin to occur. This is precisely because of these issues. With the popularity of reverse osmosis systems sky-rocketing, this issue is seen more and more often. Growers plan to use pure water, feed lightly to avoid burn and feed often to keep things pumping. This can be avoided, however, by adding back some of the original water to buffer the water once more. There is no other effective cure and throwing a calcium or magnesium product at the problem will just make it worse over time. Adding a higher concentration of nutrients is a better and safer option."

Interesting. I am using tank water that is 0.02'ish ec. I have had to add calmag as I was getting calcium and magnesium deficiencies. I suspect I have an iron deficiency in its very early stages. It basically says to supplement with your nutes instead of calmag, is that right? Anyone do it this way? About to mix up a new batch so I might try it.

Sorry for jacking your thread staygreen

clarkville, that link takes me to cannagardening.com.
don't know why.
http://www.cannagardening.com/

Yeah just click on grow info its same site man

To those still following... I think I found my problem. My tap pH is about 7.8... so I've had to use a lot of pH down to get it to 6.5. My pH down is... you guessed it... phosphoric acid. Add in the flower nutes (when this started to manifest, particularly with the aforementioned Cha Ching) and it's kind of obvious why my plants are showing physical symptoms of P-tox. Using my Brita at the moment.

Edit: Brita decreases my pH to 6.7.