Yellowing leaves, micro nutes? ~40 days into flower.

So last night my plants were fine. Today some are showing yellowing of their lower leaves. This is the first sign of real problems I have had.

►Indoor.
►About 40 days into flower. They are small plants (14-17").
►Light: 12/12 CFL (10,000 lumen 2x54w tube hood, 2x 68w CFL, and 2x23w CFL)
►Soil: MG organic in 96 fl oz containers.
►Nutes: Fed once a week at about .8 strength. Some local shit: 15-30-15
Boron- .02%
Copper- .07%
Iron- .15%
Manganese- .05%
Molybdenum- .0005%
Zinc- .06%
►Watering: every 2-3 days generously when they start to droop just a bit and the soil is obviously dry. I water with aerated tap water using an airstone after is has set out about 2 days.
►PH of water and soil has been steadily kept around 6.8.
►Temp is 70F min / 85 F Max. Humid is 23% min / 42% max.

I have read through the stickies and don't know. Plus I really have to get to work now, any help would be greatly appreciated.

Attached are photos of the most severely affected plant. The top appears fine, the fan leaf pictures is what the lower 2 nodes of leaves look right at present.

do you have your plant surrounded by cfls??? if not it could be just lack of light getting to the bottom of the canopy..

ataxia said:

do you have your plant surrounded by cfls??? if not it could be just lack of light getting to the bottom of the canopy..

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2x 54w 2 foot tubes on top (10k lumens), the 2 23w CFL are on the top. The 2x 68w CFLs are in the center of all of them.
This is a pic from last week. The plants are all tilted slightly in now so the tops are more under the hood and I have one less (herm). I rotate them every time I water as well.

dont worry about a few yellow leaves on the bottom.. That is because your using a blooming and its not high on nitrogen. Your lucky its not the top of the plants. how many weeks are you flowering for?

Unless rampant throughout the plant, it is just dropping a couple of leaves. Normal.

15-30-15 should be cool. I agree with the earlier posts that as long as its only a couple of leaves IN THE SHADE then no worries. If its happening to fan leaves getting light, even lowers, you have something amiss. Looking at your fert I don't see any Mg. You might try adding 1 tsp of epsom salts to your next water and give em a shot about once a month and see if that helps clear it up. A lack of Mg will inhibit proper N uptake no matter how much is available in the rootzone.

A fert with too much P can cause similar issues but I'm betting that is not the case this time. Too much P antagonizes uptake of Nitrogen an Magnesium. Usually only happens when using low N bloom ferts then adding PK boosters tho.

doogleef said:

15-30-15 should be cool. I agree with the earlier posts that as long as its only a couple of leaves IN THE SHADE then no worries. If its happening to fan leaves getting light, even lowers, you have something amiss. Looking at your fert I don't see any Mg. You might try adding 1 tsp of epsom salts to your next water and give em a shot about once a month and see if that helps clear it up. A lack of Mg will inhibit proper N uptake no matter how much is available in the rootzone.

A fert with too much P can cause similar issues but I'm betting that is not the case this time. Too much P antagonizes uptake of Nitrogen an Magnesium. Usually only happens when using low N bloom ferts then adding PK boosters tho.

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Thats why most ferts with P carry Magnesium. its other whys known as a bloom or budbooster product. Every dry 15-30-15 or whtever you are using should have magnesium or they wouldnt sell anything.. I have peters 10-30-20 i recommend these to anyone. Use one tablespoon per gallon untill the end and hit it with two tbsp per gallon for week 6 and 7. then flush

your plants look healthy. you should worry bout dead leaves on the bottom. It would only be a problem if it was dead buds or big leaves on the top . the lower leaves always die off. just prune them

Thats why most ferts with P carry Magnesium. its other whys known as a bloom or budbooster product. Every dry 15-30-15 or whtever you are using should have magnesium or they wouldnt sell anything.. I have peters 10-30-20 i recommend these to anyone. Use one tablespoon per gallon untill the end and hit it with two tbsp per gallon for week 6 and 7. then flush

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I agree. Also Peters BB has no Urea in it. I was using 15-30-15 but switched to Peters...Its what Uncle Ben uses.
I also agree that you need to give it some N. Give it some vegg nutes.

seasmoke said:

I agree. Also Peters BB has no Urea in it. I was using 15-30-15 but switched to Peters...Its what Uncle Ben uses.
I also agree that you need to give it some N. Give it some vegg nutes.

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It gets enough N. you shouldnt worry to much. maybe try flushing it with a qauter strenght nute mix and see what happends

Thanks for all the responses. Rep was given accordingly. I did a minor flushing the day following the post (about 1.5 times the volume of their containers). It doesn't seem to have spread much. The tops and buds are healthy looking. The fan leaves that are yellowing are getting a fair amount of light which is why I was worried. I will try the epsom salts after the next plain watering. I don't want to hit them with too much at once as the tops are fine and I don't think it is an urgent issue.
I will also look into some different bloom nutes. I have heard good things about Jacks Classic bloom nutes (10-30-20) and they are available locally. Other than that the nearest hydro shop is about an hour and 40 mins away and I wont be visiting there for about another month.

mr.smileyface said:

Thats why most ferts with P carry Magnesium. its other whys known as a bloom or budbooster product.

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When using standard nutrients a agree fully. The canna-specific nutes and additives out there are a different story.

meetzu said:

Thanks for all the responses. Rep was given accordingly. I did a minor flushing the day following the post (about 1.5 times the volume of their containers). It doesn't seem to have spread much. The tops and buds are healthy looking. The fan leaves that are yellowing are getting a fair amount of light which is why I was worried. I will try the epsom salts after the next plain watering. I don't want to hit them with too much at once as the tops are fine and I don't think it is an urgent issue.
I will also look into some different bloom nutes. I have heard good things about Jacks Classic bloom nutes (10-30-20) and they are available locally. Other than that the nearest hydro shop is about an hour and 40 mins away and I wont be visiting there for about another month.

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Jacks Classic bloom has Mg in it already but the all purpose does not. Just an FYI.

Add a tsp of epsom to a gallon of feed or regular water once a month when feeding with ferts w/o Mg.

Good Luck!

I don't think you need any more Nitrogen. The leaves are starting to claw. If anything that indicates Nitrogen toxicity. Overall looks healthy enough tho, this late in the game I wouldn't worry about micro-nutes. Maybe adjust the bloom nutes for less N and keep on truckin.

burninjay said:

I don't think you need any more Nitrogen. The leaves are starting to claw. If anything that indicates Nitrogen toxicity. Overall looks healthy enough tho, this late in the game I wouldn't worry about micro-nutes. Maybe adjust the bloom nutes for less N and keep on truckin.

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I picked up some jacks classsic 12-36-14 yesterday but they won't be getting any until Friday. I also found some superthrive at the same shop; I would have to read a bit more on that though. Ill rep burnin once I'm not on my iPod.

meetzu said:

I picked up some jacks classsic 12-36-14 yesterday but they won't be getting any until Friday. I also found some superthrive at the same shop; I would have to read a bit more on that though. Ill rep burnin once I'm not on my iPod.

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DOnt buy superthrive. try aussietonic. Its alot better. As for the classsic 12-36-14. You are going to need more K. Try added a fert of 2-7-17. That is basicly what Kushie Kush is.. Kushie Kush is what i use with my 10-30-20.. It also contains 1% MG and amino acids.... I add hyrdoboost in the start of flower mixed with diamond nectar,kushy kush,10-30-20 1tbsp per gallon and Rhinoskin(Rhinoskin is really good for silicon to make the plants fight stress,bugs,mold and anything that could hurt the plant. Its basicly building an immune system for the plant. It is also good in K but will raise Ph) And week 5 6 7 i use kool bloom,Diamond nectar, kushie kush, karbo boost mixed with 10-30-20 at 1.5 tbsp per gallon. I also add a little bit of 1-2-3, 3-2-1> General Hydro...i use promix for dirt in two gallon bags. 30 a light.. 1000w. I give them nutes twice a week and water once. and week 8 is flush

here this thread helped me. i think it will help u out. https://www.rollitup.org/marijuana-plant-problems/158144-never-ending-abuse-phosphorous-bloom.html

Rep given to all those who helped me out. Thank much. I flushed and switched to Jacks Classic bloom. Seem to be doing much better. As far as the superthrive, I don't have many options aside from an hour and 40 min drive or ordering online which I try to keep to a minimum.

Another happy Jack's customer. Right on! Keep em growin"!