Help me out here please

[maineharvest]

Ive got one strain in my tent that is not looking good. It has gotten worse just over the past 48 hours. It started just a little bit on one leaf and I just wrote it off as no big deal and then over night it has gotten much worse. Seems to be spreading from almost the top of the plant and working its way down. Not starting at the very top though, a couple sets down. I have two other strains in the tent that are not doing this. You cant really see in the pics but some spots on the leaves are turning like a black color or dark purple. now a little info.

Promix
6.8-7 ph
Strain is MOB
Started as a cutting
vegged about 3 weeks
now 2 weeks into flower
fed with Fox Farm trio
400hps
20" x 36" x 65" tent
170cfm inline fan
temps 80 degrees

Any guesses???

 

[Locked]

Not sure what the problem is but I will say she looks mucho hungry bro....way to light green for my taste.

 

[maineharvest]

The bottom half of the plant is a nice dark green. You can kinda see it in the last pic. The yellowing is working its way down.

 

[bho_expertz]

that is my bet also. hit her with higher dosage.

 

[Locked]

I wld up the nutes, recal my ph meter and see if she improves...jmo

 

[maineharvest]

Ok sounds like Ill give a heavy feeding. Thanks guys.

 

[Growdude]

Its a Phosphorus deficiency, here is a picture of it.

http://www.marijuanapassion.com/forum/showpost.php?p=243329&postcount=7

 

[maineharvest]

I thought it looked like phosphorus too but it is going from top to bottom and that is the opposite of what phos def does.

 

[maineharvest]

Could it be a lock out of one or more micro nutrients that are mobile due to the ph? Is a ph of 7 to high?

 

[bho_expertz]

I always give water between 6,3 and 6,5. 7 is high i think.

 

[ozzydiodude]

Fix your ph to 6.3 to 6.5 and see if the new growth starts looking better.

 

[Locked]

6.5 for everything in soil for me.

 

[jbyrd]

I would start with PH and lockout as well. 7 is high, 6.5 is good, anywhere in the 6.3 - 6.8 range should be fine in soil. When you water/feed I would water heavily in the lower PH range this time (6.3). Try to get the medium's PH down in to optimum range.

 

[maineharvest]

Ok thanks yall.

 

[Wetdog]

I thought it looked like phosphorus too but it is going from top to bottom and that is the opposite of what phos def does.

Just what I was thinking.

Looking in my handy dandy "Marijuana Garden Saver", indicates a Iron, manganese, zinc deficiency. The 3 usually happen together and supplements usually contain all 3.

And it happens from the top down.

Wet

 

[Wetdog]

Could it be a lock out of one or more micro nutrients that are mobile due to the ph? Is a ph of 7 to high?

A bit, but not all that much, not super lockout high.

I'd bet a quick foliar shot of micros will give you the best results right now. Do you have anything like that around? Any *Ironite* or the like?

Wet

 

[nouvellechef]

What's PH?

 

[Wetdog]

He said 6.8-7.0.

Wet

 

[maineharvest]

Im thinking it is a zinc lockout caused by ph over 7. The zinc lockout is effecting the phosporous uptake and that would explain the darkening. I did a little research in the Bible and I think ive got it figured out. I did a flush with water ph'd to 6.5 with a light dose of Tiger Bloom and will do a foliar feed of Grow Big. Hopefully this helps or else Im throwing these things in the dirt outdoors.