Black Spots on Defecient Leaves

[romdog11]

Pics are up. here is the story. i have these black spots appearing on my leaves on a defecient plant. its losing a lot of fan leaves and ive never seen this before. im growing in soil and im using cns 17 bloom and big bud at an ppm of 1200. if you need any more info please ask. also the ph is around 6.6. i feed my other plants with the same feed regime (once a week) and none of my other plants are showing any signs. heres a older pic of my plant with its fan leaves but now all those yellow leaves are gone.

 

[MynameStitch]

You have different strains?

Need more information;but the black spots I can't see to well; all I can see is that you have a nitrogen deficiency; how far along is she in flowering? From the time you flipped th switch over to 12/12

SOIL:
What STRAIN are you growing?
What was the establishing technique? (seed or clone?)
What is the age of your plants?
What PHASE (seedling, vegetative or flower) are the plants in?
What Technique are you using? (SOG, SCROG etc)
What size pots are you using? (Include how many subjects to pot)
What substrate/medium are you using? (percentage of perlite, vermiculite...etc?)
What Nutrient's are you using?How much of each? How Often? *Knowing the brand is very helpful*
What is the TDS/EC/PPM of your nutrients used?
What is the pH of the "RUN-OFF"?
What method of pH test was administered? Using Strips? pH pen?
How often are you watering?
When was your last feeding and how often are you feeding?
What size bulb are you using?
What is the distance to the canopy?
What is your RH Factor? (Relative Humidity)
What is the canopy temperature?
What is the Day/Night Temp? (Include fluctuation range)
What is the current Air Flow? (cfm etc.)
Is the fan blowing directly at plants?
Is the grow substrate constantly wet or moist?
Is your water HARD or SOFT?
Has plant been recently pruned, cloned or pinched?
Have any pest chemicals been used? If so what and when?
Are plant's infected with pest's?

 

[romdog11]

SOIL:
What STRAIN are you growing? mandala sadhu and 2 others
What was the establishing technique? (seed or clone?) seed
What is the age of your plants? about 4 weeks into flowering sporuted on 9/19
What PHASE (seedling, vegetative or flower) are the plants in? flower
What Technique are you using? (SOG, SCROG etc) ummm newbie style
What size pots are you using? (Include how many subjects to pot) big ones!
What substrate/medium are you using? (percentage of perlite, vermiculite...etc?) fox farm and light warrior
What Nutrient's are you using?How much of each? How Often? *Knowing the brand is very helpful* CNs 17 bloom with big bud
What is the TDS/EC/PPM of your nutrients used?ppm have been at 1200 but i just fed her a feeding of 1600 ppms
What is the pH of the "RUN-OFF"?not sure
What method of pH test was administered? Using Strips? pH pen?oakton pen
How often are you watering? when the first inch of the soil becomes dry.
When was your last feeding and how often are you feeding?once a week but gave a boost today
What size bulb are you using? vegged under a 400 mh flowering under a 600 hps
What is the distance to the canopy?about 12 inches
What is your RH Factor? (Relative Humidity)30
What is the canopy temperature?not sure
What is the Day/Night Temp? (Include fluctuation range)77 all day
What is the current Air Flow? (cfm etc.)
Is the fan blowing directly at plants?no
Is the grow substrate constantly wet or moist?no
Is your water HARD or SOFT?soft
Has plant been recently pruned, cloned or pinched?no
Have any pest chemicals been used? If so what and when?no pest strips
Are plant's infected with pest's?none

 

[romdog11]

here are the pics that are recent as in today.

 

[blueberryfarmer]

Dude thats pretty much EXACTLY what I'm experiencing right now too. Check out my thread. I'm growing in DWC hydro! I wonder what the hell this is.

http://www.icmag.com/ic/showthread.php?t=72717

 

[moonymonkey]

looks like locked up,ph imo.

 

[romdog11]

i was thinking the same thing. every feeding i give it with nutrients the ph is around 6.5 when i give it plain water i use vinegar to lower my ph. do you think my problem can be with me adding the vinegar?

 

[HeadyPete]

When was the last time you gave nitrogen? That's what happens when you feed all bloom right off the bat at 12/12 and all strains are different in their feeding requirements. Hell, all phenos of the same strain can be different in it's size, shape, nutes, water etc. It's evolution, baby! This one stretched (thus still wanted nitrogen) when you switched the light and used up it's stored N real good, hence the yellowing leaves.

Next time give some N for 2 weeks after switching, then you can stop and just feed bloom. Yellowing fan leaves at harvest are a good thing.

I also think you are feeding too strong. Some of that damage is lockout (black spots = calcium def it looks like - too much phosphorus will lock out Cal) and there is good tip burn, plus those clawed, down-curled leaves, means ferts too strong. Ease off and watch your plants for these symptoms. A little tip burn is what you want. I think you will see some real good tip burn after that last feeding. Less is more!

 

[HeadyPete]

Next time you water, collect the runoff water from the bottom of the pot and measure it's ph. Adjust your fert water accordingly to get the runoff to 6.5. If runoff is high, lower fert ph. If runoff is low, raise ph of ferts. Ph swings are not good.

Vinegar is not a stable or strong acid for lowering ph. The best two ph downs I like are Phosphoric Acid 20% (non organic, potent=little needed, adds phosphorus to ferts, benefits flowering) and Fulvic Acid, specifically Grotek LXR Gold. This is not as strong, so you use more, but it is organic and aids your plants in the uptake of nutrients, allowing you to use less ferts to get the same results. There are many benefits to fulvic acid. I like to use both, but I am out of fulvic right now and just using P Acid.

 

[Wicked]

thats all very helpful, i was having some brown spots on some of my leaves..and only on one plant outta five. All the same kind , a bag seed.

 

[MynameStitch]

1200 but i just fed her a feeding of 1600 ppms

THats a lot of nutrients for soil growing.... I would have backed that down to about 1,000 to 1200 max.


CNs 17 bloom
What is that? How much big bud and that are you using anyways?

You are not sure of your ph, you could have issues, that spotting is most likely the cause of pH not being stable which leads lockout.. the nitrogen is being caused by no nitrogen into your feeding regimen How far into flowering are they now? If they are about 4 to 5 weeks let them yellow as this is natural towards the end of harvesting as long as it's going to be harvested in the next 2 weeks.... longer harvest times require nitrogen around this time if it's showing issues....

You need to water your plant and make sure your pen is re calbrated and collect the run off and wait a min to test it and get your pen and make sure you have enough to correctly test it and get the ph reading there... your ph should be around 6.5 to 7.0.....
if it's above to below that range you need to fix it.

 

[-VT-]

CNS-17 has a high Ca content....running higher pH with CNS-17 is asking for trouble...but...I have never used it in soil (only used it in coco coir).. had pH lockout in coco messing with high pH and CNS-17....I had pH lockout and my plants looked like those ugly leaves you pictured...

Using Big Bud with CNS-17...I dunno about all that....

good luck

 

[romdog11]

thanks for the help everyone. on a side note the first week of flowering i gave it a feeding of bloom and grow. i also did that again in the 4th week. so the nitrogen is a mystery to me. i do have other plants that use the same water mixed with nutrients during feedings and they arent doing what im seeing. so i dunno

ps next time i water ill collect the run off ph. thanks again everyone for the help

 

[HeadyPete]

That one wants more N. Never mind what the others want. It's apples and oranges. I'd like to see the others to see what shape they are in.

I feed N every watering every week (with plain ph adjusted water every 3rd watering) from a week after sprouting until 2 weeks after switching to 12/12. What I alter is the strength of the nutes each time to match what the plant wants. There is also BioBizz dry nutes in my cocosoil so my doses at the beginning account for that.

My moms get 1/2 strength BioBizz gro (1/2 mL/L), which is already a mild organic nute, vegging plants get full strength (1 ml/L)and full strength 2 weeks into flowering then I go half strength for 2 weeks, then no gro at all for the rest of flowering. You need to know how long your plant takes to finish to calculate all these feeding changes. For instance, one pheno of LUI I have is on day 90, and I cut back gro and started final flush too early, resulting in dying crusty fan leaves. Not a huge problem, but had I extended the whol;e regime for a week, I would have ended up with yellowing fan leaves with no crusty spots.

My other pheno seems to be an early one and my 3rd pheno is later again. see how you need to know your plants?

Feeding N in the 1st and once in the 4th week of flowering is not enough feeding, hence your results. It's obvious that you didn't give enough N in veg to get to this point.

As soon as you see one lower fan leaf start to fade and yellow evenly, with no green veins in the middle (that's mag def and it starts on the upper part of the plant), you are lacking N. NPK are called macro nutrients because plants (all plants) require these in the most quantities. Secondaries, Calcium, Magnesium and Sulfur. Micro nutrients are manganese, boron, copper, iron, chlorine, cobalt, molybdenum, and zinc.

from http://www.answers.com/micro nutrients

Micronutrients for plants

There are about eight nutrients essential to plant growth and health that are only needed in very small quantities. These are manganese, boron, copper, iron, chlorine, cobalt, molybdenum, and zinc. Some consider sulfur a micronutrient, but it is listed here as a macronutrient. Though these are present in only small quantities, they are all necessary.

Boron is believed to be involved in carbohydrate transport in plants; it also assists in metabolic regulation. Boron deficiency will often result in bud dieback.

Chlorine is necessary for osmosis and ionic balance; it also plays a role in photosynthesis.

Cobalt is essential to plant health. Cobalt is thought to be an important catalyst in nitrogen fixation. It may need to be added to some soils before seeding legumes.

Copper is a component of some enzymes and of vitamin A. Symptoms of copper deficiency include browning of leaf tips and chlorosis.


Iron is essential for chlorophyll synthesis, which is why an iron deficiency results in chlorosis.

Manganese activates some important enzymes involved in chlorophyll formation. Manganese deficient plants will develop chlorosis between the veins of its leaves. The availability of manganese is partially dependent on soil pH.

Molybdenum is essential to plant health. Molybdenum is used by plants to reduce nitrates into usable forms. Some plants use it for nitrogen fixation, thus it may need to be added to some soils before seeding legumes.

Zinc participates in chlorophyll formation, and also activates many enzymes. Symptoms of zinc deficiency include chlorosis and stunted growth.

 

[MynameStitch]

THanks heady you saved me time bro!
Heady pretty much summed it up; but there was a few things I wanted to add on this post.

thanks for the help everyone. on a side note the first week of flowering i gave it a feeding of bloom and grow. i also did that again in the 4th week. so the nitrogen is a mystery to me. i do have other plants that use the same water mixed with nutrients during feedings and they arent doing what im seeing. so i dunno

ps next time i water ill collect the run off ph. thanks again everyone for the help

Every strain is diferent, if you get a clone and seed it's different, only way to get the same care in plants is to get the same clone from the same plant.

You need to feed weekly, not just once or 2 times......

weekly is what you need to feed for your situation.....

 

[HeadyPete]

my pleasure, Stitch!

 

[romdog11]

hey would it help if i posted my feeding schedule? i have everything written down with dates and ec level. tell me if you can use more info!

 

[MynameStitch]

Yes, that would be useful

 

[romdog11]

ok this is that plants history
sprouted on 9/19 thourghout veg. stage fed an ec of 1.6 fox farm grow and liquid karma.
12 inches on 10-26 and put into flower
10-27 fed grow and bloom cns 17 ec 2.2
11/4 bloom and big bud ec 1.8
11/13 bloom big bud ec 2.4
11-18 bloom big bud ec 2.6 (problems begin to appear around now mostly def. of nitrogen)
11/22 bloom ,grow,big bud ec 2.6 (losing leaves)
11/23 blooom ec 3.2

thats about it. it gets fed and when i put the nutrients in the mixer they come to ph 6.6 the only thing i can think of is when i feed it plain water i have to adjust the ph maybe im not doing that right.

 

[Quiet_Riot]

Overfeeding and N-def and then lockout, a bummer, man. Try to clone some and run different regimes on them, to dial in. And maybe try to bubble your water a day, before using it. Although the ph of 6.6 is fine..