Green Crack Day 38 Flower in 10 gallons of soil...

Hello

Hoping to get some expert opinion on a plant problem I have. These are in 10 gallon soil pots and are on day 38 in flower. Some of the top leaves are yellowing and curling. The leaves effected seem to be most directly under the light, and higher up on plant branches. The leaves effected are mostly on the main branches of the plant. I'm sorry about the poor picture quality, hopefully they are still useful.

Possible problems:
Water quality. My water comes out of the tap at 7.8-8.5. On the water quality report it says a PPM of 275. I run it through a tall boy filter but it just removes chlorine and sediment.

Overfeeding. The plants have gotten something almost every feeding in flowering. They are fed at weak strength, regularly. When the problem first started to get severe I showed a fellow ICmager and this was what he thought.

Thanks for any and all input!

Pictures
Day 19 flower... you can see some initial yellowing on leaves in the middle


Day 27 flower... on the first pic you can see the yellowing in the middle has gotten a bit more severe. On the second picture there are some yellow tips... is this normal? I thought burnt tips would be more charred




Day 38 flower... much more severe yellowing on the sides of the leaves. Some especially effected leaves are curling down and then up.






And the form...


How long has this problem been going on? 20 days or so.
What STRAIN are you growing? Green Crack
What was the establishing technique? (seed or clone?) Clone
What is the age of your plants? 100 days old, 38 days in flower
How long have they been in the soil mixture they are in now? 64 days
Were they in the same mixture when they were seedlings/smaller plant? If not, what mixture were they in before? yes, they were in the same mixture
How Tall are the plants? 35" total, woven through a screen that is 18" above the plant
What PHASE (seedling, vegetative or flower) are the plants in? 38 days flower
What Technique are you using? (SOG, SCROG etc) screen
What size pots are you using? (Include how many subjects to pot) 10 gallon pots, 1 per pot
What substrate/medium are you using? What brand of soil mixture are you using? (percentage of perlite, vermiculite...etc?)

Roots Organic Base
+10% Perlite
+1 tbs dolomite lime per gallon
+1 tbs mosquito dunks per 3 gallons
What brand Nutrient's are you using? Humbolt Nutrients Master A+B, Prozyme, Sea-Cal (Cal product), Sea Mag (Mag Product), Humic Acid, Fulvic Acid, Humbolt Roots (Benefical Bacteria Product), Myco Madness, Bloombastic
How much of each nutrient are you using with how much water? *Knowing the brand is very helpful* 1/2 to 3/4 strength nutrients every time
How often are you feeding? Plant receives Master A+B, Sea Cal or Sea Mag (whatever schedule calls for) + the other nutrients every other time. On the off watering, plant receives the other nutrients. This is at 1/2 to 3/4 strenght
If flowering, when did you switch over to using Bloom nutrients? Have used Master A+B both times since switching the flowering, except most recent watering which was just water, and the previous watering which was only master B (high in PK)
What order are you mixing your nutrients? (example: veg nutes 1st, bloom 2nd ect) bloom 1st, everything else 2nd.
What is the TDS/EC/PPM of your nutrients used? No EC tester
What is the pH of the "RUN-OFF"? 7.2
How often are you testing pH/ppm/EC/TDS? Test PH of nutrient solution and adjust to 6.5 before every watering. Have tested runoff twice.
What method of pH test was administered? Using Strips? pH pen? Liquid test kit
How often are you watering? 1-1.5 gallons every 3-4 days
When was your last feeding and how often are you feeding? Last fed 7 days ago, but previous to that I have been feeding 1/2 to 3/4 strenght every time.
What size bulb are you using? 1000w HPS
How old is your bulbs? brand new
What is the distance to the canopy? 20"
What is your RH Factor? (Relative Humidity) 50-60%
What is the canopy temperature? 77
What is the Day/Night Temp? (Include fluctuation range) 73-77 DAY 65-70 NIGHT
What is the current Air Flow? (cfm etc.) 375 CFM fan exhausting for 30 seconds every 5 minutes
Tell us about your ventilation, intake exhaust and when its running and not running ? On an interval timer, 30 seconds on 5 minutes off
Is the fan blowing directly at plants? No
Is the grow substrate constantly wet or moist? I water when I can stick my finger in the soil and the very tip feels very close to being dry.
Is your water HARD or SOFT? Hard water, PH of 7.8-8.5
What water are you using? Reverse Osmosis (RO)? Tap? Bottled? Well water? Distilled? Mineral Water? Water is run through a Tall Boy Filter
If using tap water, what is the ppm/EC/TDS of the water right out of the tap?(Only if you have a tds pen) Don't have a EC Pen
If using RO,Distilled,mineral water, what is the ppm/EC/TDS without any additives?(Only if you have a tds pen) No EC Pen
Are you using water from a water softener? no
Has plant been recently pruned, cloned or pinched? no
Have any pest chemicals been used? If so what and when? not recently, in the past, just neem.
Are plant's infected with pest's? There are some fungus gnat adults flying around. 30 flyers are stuck to a sticky trap thats been in the room for 50 days.


edit: problem going for 20 days not 2 days

Its looking like phosphorus is being locked out.

It is impossible to tell by your pictures, but are your stem and petitoles turning red/purple?

by the looks of those yellow leaves it either ph or your soil is to salty which is causing root lock. I would do a heavy watering with some clearex flush out the salts. I have grown green crack before and that bitch has some beautiful buds but she is a moody bitch. My guess would be your soil is to salty. Are you getting a lot of dead yellowing leaves?

dude you slightly fried them with nutes. I would flush with clearex or plain ph'd water and then refertilize. Shouldn't you be flushing? Green crack is a 45 day strain. Good luck!!!

johnnyla said:

dude you slightly fried them with nutes. I would flush with clearex or plain ph'd water and then refertilize. Shouldn't you be flushing? Green crack is a 45 day strain. Good luck!!!

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Sorry off topic a little. Green crack is a 45 to chop strain? This would be great news to me. Have any links for details?

Herborizer said:

Sorry off topic a little. Green crack is a 45 to chop strain? This would be great news to me. Have any links for details?

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Well, depending on how legitimate your cut of the GC is, yes. I like to pick it from anywhere from 49-56 though.

I've had buddies get so-called green crack cuts from some lowly clubs here in nor-cal, and those cuts never resembled the green crack as I knew it.

In my experience, you can't mess up (it's hard at least) growing this strain, so I disagree with the person who said she's a moody bitch (but hey, it's just my opinion).

My question is how close are your lights to that canopy? The fact that it's mainly showing on the plants in the middle, might be light burn.

I agree with Tokinafaty420.
It looks to be Potassium Deficency.

Phosphorus is lacking or being locked out. Wouldn't get crazy adding a buch of P to correct. Leach/flush with plain pH'd water, let dry out and then gradually up the feed level. Will prolly be flush time by then so...remeber what they like for next run. Herb should still be fine though... Plants look fine all around.

Green crack is a rare phenotype of Super Skunk which is a 45 day plant. I'm talking about cuttings in CA. obviously if you grow from seed you can have variances.

When I grew green crack I let it go for 49 days. That was when the trichomes were half milky and half brown. Little body high but mostly head high.

johnnyla said:

Green crack is a rare phenotype of Super Skunk which is a 45 day plant. I'm talking about cuttings in CA. obviously if you grow from seed you can have variances.

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WRONG! I have to call BS when i see it. Maybe you cali folks got your own rendition of GC but the original is actually SKunk #1 crossed with an unknown indica male from athens georgia in 1989 made by CecilC originally named Cush. Re-named Green Crack by a grower named Bunz in southern California supposedly after snoop dog called it green crack. Sorry to call you out man but that just seems to be a major misconception amongst the community. Cali has so many dank strains that we can't give yall all the rep for the few Dank US strains from else where.

Now to the diagnosis. What's up FS? how ya doing man! I would say that you probably gave them nutes too often which lead to a salt build up. How often do you water? I was told the rule of thumb for using nutes is to feed and then use straight water the next two times to flush out any salts and you make it sound like you feed em every other watering instead. I will let you know that I am an organic soil buff and have very little experience with ferts but I have read plenty.

Overfeeding. The plants have gotten something almost every feeding in flowering. They are fed at weak strength, regularly.

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If you check out this thread, https://www.icmag.com/ic/showthread.php?t=11688 I'm sure you would agree that it looks a lot like photo 2 for phosphorus deficiency in flowering. I also don't like the look of how the veins of the leaves are super green while the rest of the leaf is yellow so you might have a magnesium defeciency as well.Then again, it's not a very good picture w/ the HPS orange spectrum disorienting my color perception and you said you feed w/ Sea Mag often. If you have the option, I think better pics would help us help you in diagnosing this problem. If your camera has a white balance, play with it a little and I'm sure you can have better pics with that HPS glow.

On a sidenote, squirrel I think your green crack looks pretty legit to the original. No more than 5 blades per leaf accompanied by a big, phat F-U finger in the middle. I can't comment on the structure because it is a sea of green (that's a good thing) hindering my view. I'm guessing your using 1k watts to be getting that kind of canopy penetration w/o pruning?

The fan leave stems are turning purple but the meristem and other branches are still green. Does this mean that I have a Phosphorus def or lockout? The runoff PH is high which would make me think lockout but I look at the nutrient availability chart and it looks like P gets locked out at lower Phs.

There are not that many dead leaves. Some leaves are slowly dying from the bottom up but at this stage in flowering I think that is normal.

The plants are 20" inches from the Supersun ll reflectors. I don't suspect light frying because they have gotten dramatically worse in the last 3 weeks whereas they have been under the same lights for almost 60 days.


I'm watering between 1 and 1.5 gallons every 3-4 days. Everytime I water they get something, either humic/prozyme/myco or humic/prozyme/myco/masterA+B/seacal or mag/bloombastic. I will play around with photoshopping the pictures when I pick my laptop up from the shop on monday. Yes, this cut of GC has been in my circle for almost 10 years, its the real deal.

Thanks everyone who stopped by to offer their input!!!!! But I'm still open to hear more!

you are giving them to much nutrients. Give them nutrients every other time you water. Your roots have nutrient lock.

Weird, man! I'm at day 38 of a green crack grow right now as well. I'm in hydro, but I've found that GC is extremely nute tollerant. I've hit 2000 ppm a few times, and no nute burn yet. I've also found that she doesn't like pH flux.

I'll take some pics in the next few days, I'll be flushing soon.

I'd guess this is more like a 50 day strain. I took some samples at day 30, and it was very strong for a plant at 30 days, but the GC flavor just wasn't there yet.

The smell is INTOXICATING! I find myself dazing off when I'm in the flower room.