Help: Leaf tips of mother plant are turning black

[overmind1632]

How long has this problem been going on? 2 weeks
What STRAIN are you growing? Apollo 11
What was the establishing technique? (seed or clone?) Clone
What is the age of your plants? 4 months
How Tall are the plants? 6 inches
What PHASE (seedling, vegetative or flower) are the plants in? Vegatitive
What Technique are you using? (SOG, SCROG etc) None
What size pots are you using? (Include how many subjects to pot) Bonzaii Mom pot
What substrate/medium are you using? What brand of soil mixture are you using?(percentage of perlite, vermiculite...etc?) Soil with like 25% perlite
What Nutrient's are you using?How much of each with how much water? How Often? *Knowing the brand is very helpful* Miracle Grow
What is the TDS/EC/PPM of your nutrients used? idk
What is the pH of the "RUN-OFF"? idk
What method of pH test was administered? Using Strips? pH pen? idk
How often are you watering? 1-2 times a week
When was your last feeding and how often are you feeding? 2 weeks ago and about 2 times a month
What size bulb are you using? 2 daylight CFLs at 26 watts each
What is the distance to the canopy? 4 inches
What is your RH Factor? (Relative Humidity) 50%
What is the canopy temperature? 80 F
What is the Day/Night Temp? (Include fluctuation range) 80-60
What is the current Air Flow? (cfm etc.) 0
Is the fan blowing directly at plants? no
Is the grow substrate constantly wet or moist? moist
Is your water HARD or SOFT? medium
What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water? tap
Has plant been recently pruned, cloned or pinched? yes, trained to stay as bonzai mom
Have any pest chemicals been used? If so what and when? once to kill fungas gnats like a month ago
Are plant's infected with pest's? not at the moment

Could it be a Phosphorus deficiency?

Thanks for the help guys

 

[stinkyattic]

No ventilation
Night temps=60
Pot size not given, pH numbers not given.

When was the last time you did a good heavy flush? I'd flush well with water at correct pH to bring your runoff to 6.7 and then let it dry out fairly well before doing your root pruning.

Please post pics and give your poor plant some fresh air.

 

[overmind1632]

No ventilation
Night temps=60
Pot size not given, pH numbers not given.

When was the last time you did a good heavy flush? I'd flush well with water at correct pH to bring your runoff to 6.7 and then let it dry out fairly well before doing your root pruning.

Please post pics and give your poor plant some fresh air.

Plant doesnt need ventilation because its like 6 feet from an open window out in the open

Wouldnt flushing make the Phosphorus deficiency even worse if it is one? The pH im sure is around 6.5-7.0.

 

[stinkyattic]

WEll, you're using Miracle Grow- it's NOTORIOUSLY prone to salting up yoru soil.
A correct flush always finishes with a watering of your base fert mixed at half strength. So no, that would not make P def worse. If that is what you suspect, do that watering with a cannabis-specific bloom fertilizer instead of a grow fert. I give my moms a diet that includes feedings with bloom ferts before clones are taken, to help encourage root growth in the cuttings.

 

[overmind1632]

I'm not 100% sure it is a Phosphorus deficiency or not

Anybody else have any opinions or input?

 

[stinkyattic]

Pictures would be REALLY helpful...

 

[overmind1632]

I know but I dont have a camera

THe thing is, the problem I am trying to describe looks a lot like the P def. described in the sick guide sticky

 

[stinkyattic]

Okay, I trust you on that. Either way, with a history of MG use (I think you can be denied health insurance for that or something hahaha) you definitely want to flush your soil and feed with a nute you KNOW is providing the nutrition your plants need. I tend to believe that if you suspect soil salting due to pre-fertilized soil or poor quality ferts, that you should switch to a liquid organic like Pure Blend Pro or Canna Terra, both of which have humic acid in them and will help keep your soil pH in range along with preventing further salting of the soil. Humic acid is both a pH buffer and a chelator! And if you are trying to treat P def or lockout, first you have to make certain it's not just locked out (hence the flush and use of a pH buffered fertilizer) and then return it to the plant with a good bloom fert. Bloom ferts always contain a high proportion of Phosphorous. Mmmm Canna Terra Flores...
Good luck!

 

[overmind1632]

I plan on watching the plant for another few days beacause atm, it is just a few leaves that are minorly affected. I tested my water and run off and the pH is between 6.5-7.0 like I expected. If more leaves continue to blacken, I will flush and feed with high P fert on next watering

 

[stinkyattic]

Just out of curiosity... is there any possibility that sitting near the open window your plant may have taken a frost?

 

[overmind1632]

Just out of curiosity... is there any possibility that sitting near the open window your plant may have taken a frost?

Its not close enough to the window to frost and it hasnt been cold enough outside to frost either

My estimate for the lowest its ever been is 60 but on average is hovers between 70-80

In general, the mother plant is very healthy, im sure it will be fine in the long run

 

[highallthetime]

PH is 99 % to blame. Check it often.

 

[overmind1632]

PH is 99 % to blame. Check it often.

I did, its fine so its not a PH problem

plus if it were a pH problem, i would have easily identified it ( I think )

 

[highallthetime]

How old are they ? PM me if you wish. Did you test both run off and soil or soiless ph ?

 

[Weedninja]

Dude, take that MG and beat it with a baseball bat. It's friggin' junk. If you want a fert that's easy to find, try Peter's(chem) or Plant-Tone(organic). I saw Plant-Tone at K-Mart.

 

[overmind1632]

Ok, im not using MG, its called Expert Grow but im sure its the same as MG

anyways, ive used Expert Grow for 2 grows and never had any problems with it

The mother plant is like 4 months old, I tested run off and water pH and both were fine