Heat/light problems or nutes?

[Guest]

Space: ~18" x 47" enclosed
Light: 400w HPS vented(AC)
Time: 4wks 12/12
pheno: dominant sativa traits
Current Food:
mixed in one gallon intervals: One TBLS Super Bloom 12-55-6, dropperful of Superthrive, and was adding a TBLS of Neptunes seaweed/fish emulsions 2-3-1 but recently stopped when the conditions were observed. Feeding usually two gallons of solution to six 10" planters.
Thanks!

 

[Rosy Cheeks]

It looks to me like it's a top foliage problem, so I would say heat stress, but that's not a definite diagnosis. A few weeks into flower under HID light, large leaves often tend to loose in vigour and lustre, especially if temps are high and humidity is low. It shouldn't scare you, because the plant will prioritate bud growth and foliage will suffer.
I don't know the nutrients you're using, but any flower nutrient containing twice as much Nitrogen as Potassium is not made for flowering Cannabis. The fish emulsion additive is equally boosting the N levels. N should be much lower and K levels much higher. Secondly, superthrive contains plant hormones that stimulates foliar growth and not flower growth, so you don't want to use it in flower, only in veg. I don't know what strain you're growing so I cannot comment on the flower production, but my gut feeling tells me you should have bigger buds on those plants after 4 weeks of 12/12.

 

[Guest]

Thanks for the input! What readily available fert would you recomend for the flowering?
I also have Jacks 10-30-20 in my arsenal that would seem to be better...??

 

[sproutco]

Without even really looking at the pictures I can tell you using 12-56-6 is providing too much phosphorus. Plus, my version contains only iron as the micronutrient. This can lead to manganese, zinc, or copper deficiency especially manganese first. It is also 100% ammonium nitrogen which can lead to ammonium toxicity and calcium deficiency.

The Jacks Classic 10-30-20 would be better because it contains all the micros and is about 50% nitrate and 50% ammonium nitrogen. I would try about 1 teaspoon per gallon. It is a bad fertilizer because it contains .05% zinc and copper and this can lead to toxicity because it is alot.

Check your labels and see if what I said matches up.

 

[Guest]

Awesome thanks!
My last effort was using two 42w CFLS and a 75w HPS and a 50wHPS (homemade) and yielded this with the 12-55-6 crap + superthrive. The first at 6.5wks and the second one of the bigger tops. Not bagseed but rather a little mutty of some decent genes...

 

[sproutco]

Remember that both 12-55-6 and 10-30-20 contain no calcium and very little magnesium and sulfur. You should have dolomite lime and gypsum in your soil to provide calcium, magnesium, and sulfur. You can also add these along with either fertilizer if needed by using 1/4 (1.25ml) teaspoon of both epsom salts and powdered gypsum in 1 gallon of water (3.8L). Even with dolomite lime and gypsum in the soil, I might add the cal/mag/sulfur in the water every third or fourth time I fertilize. If you can't get powdered gypsum to add to your water you can substitute calcium nitrate at the same rate but this will add nitrogen. (not much)

 

[Guest]

Right on. I forgot to mention I have been adding epsom salt recently as our water is extremely hard and I heard that's the way to go. Too late obviously to amend the soil with lime, Can I add it another way? the gypsum I have available at a local garden supply center I'm pretty sure...

EDIT: I forgot also to mention that I have taken a small piece of soft coated nylon replacement window screen and made a small canopy directly under the light which has slightly shaded the lights footprint and dramatically reduced temps at the tops of the plants. I really was never over 89deg beforehand though...do you think this was necessary even with that light bleeching look and all?

 

[sproutco]

You should not need a screen to shade your light. You want as much light as possible. Here is the lighting distance chart for a high pressure sodium: http://www.icmag.com/ic/gallery/showphoto.php?photo=150896&sort=1&cat=500&page=1 I would try about 12-15" away and see if your hand is too hot at the plants tops. 89 degrees is not too hot. Stop using the 12-55-6 and switch to the 10-30-20 at about 1 teaspoon per gallon of water. If your water is "hard" with calcium then you might not want to add any extra gypsum to your soil and water because this would add more calcium. It would have been a good source of sulfur. You can get sulfur from the epsom salts if you add this with every watering or only every third or fourth watering depending on whether you have dolomite lime in your soil to supply magnesium and its effects have not "run out".

 

[Rosy Cheeks]

Thanks for the input! What readily available fert would you recomend for the flowering?
I also have Jacks 10-30-20 in my arsenal that would seem to be better...??

I suggest you get a nutrient that has proven itself in growing Cannabis, such as General Hydroponics, Bcuzz or Ionic among salt based nutrients, or Pure Blend Pro, BioBizz or Earth Juice among organic nutrients. In veg, Cannabis needs a lot of Nitrogen (N) to grow, and in flower it needs a lot of Phosphorus (P) and Potassium (K) for flower development and much less N, meaning that you're better off to change nutrient composition when you go from one to the other. Most good nutrients have a veg-nutrient and a bloom-nutrient.

Right on. I forgot to mention I have been adding epsom salt recently as our water is extremely hard and I heard that's the way to go.

No! Hard water is hard because of excess levels of Calcium (Ca) and Magnesium (Mg), so that's not a reason to add epsom salt (Magnesium sulfate). Cannabis use almost as much Mg and Ca as Macronutrients (N,P and K), so hard water's perfect for Cannabis growing, but overdosing Mg can lead to Ca lockout, and vice versa, so too much of either's no good either. Add epsom salt only if your plants show a Mg deficiency. Getting a complete, well-balanced nutrient in combination with your hardwater is probably the easiest solution for you, if chemistry is not your thing.

 

[Guest]

Ok so in summation:
Based on those pics, screw the light shade? (I'm > 12" away and about 89deg)

Switching to the Jack's Classic 10-30-20 (which supposedly has Magnesium)
Was going to switch to a distilled water to skip the hard water thing....I thought I was getting a Magnesium lockout(thus the epsom salts) so dunno there...
The unfortunate part is these girls are only drying out every other day or more so it's hard to "switch" things up. It also seems that the ones on the right side are looking worse then the left (thus I thought it was a heat/light problem based on fan/vent orientations but damn 89 isnt that bad...

OHHHH and most importantly <toke> I forgot to mention that I do have some fungus gnats....enough that when the girls dry out there is bodies litering the floor of the cab. Bought some Garden Safe neem oil based spray and have been recently treating the soil tops (I don't spray anything on the plants no matter how safe shit says it is)..

Hope this grow finishes well so I can rethink the Widows I'll be starting next...

 

[sproutco]

I was going to mention...hold on while I roll a joint...okay. A tablespoon of 12-55-6 per gallon of water is alot of fertilizer. This would be a huge dose of phosphorus. Then you added more ferts like fish ferts or whatever. Hold on let me light the joint...Okay [joint slowly burns] The Jack's classic contains .5% magnesium [takes a toke] which would be 6 ppm magnesium at 1 teaspoon per gallon of water. This is not really much at all. Normal hydro rate is 30-50 ppm. [takes toke of joint] But this small dose could ward off magnesium deficiency if there is already dolomite lime in your soil.

 

[Guest]

Mother F'ers!!!!
The problem has GOT to be these bitches....

FUNGUS GNATS!! What once was a few harmless buzzers is now littering the floor with their carcasses during dry outs. In fact the soil dosnt even dry out any more just the plants... ALL have suffered and had to remove one completely at only 5wks...I have flushed with distilled water and started using a heavy spray app of Neen oil extract on the soil tops and plant undercarriages (not the tops as this shit smells horrible)...in the mean time, foliar feeding with dillute Sweet and Bio-Bloom spray which seems to be helping as the plants are obviously not drawing from the soil.
AAAAAAAAAAARARRRRRRRRRRRRRRRRGGGGGGGGGGGHHHHHHHHHHHHH!

 

[Rosy Cheeks]

Could be. Fungus gnat larvae in the soil feed on finer root hairs, which then can produce problems that looks like some kind of feeding/root problem.

 

[sproutco]

I was wondering if this could be ammonia toxicity. In Poinsettia plants it shows interveinal chlorosis (yellowing between the veins), white patches on the leaves, curl down, and "droopy" lower leaves. Possibly resembling calcium deficiency in some plants. It can also burn roots. 12-55-6 that he was using in such a large dose is 100% ammonia rather than nitrate nitrogen.

This is the only quote I could find offhand...

Ammonium toxicity. This is not so common anymore because most growers use water-soluble fertilizers that supply about 50/50 ammonium and nitrate to fertilize plants in soilless media

http://www.umass.edu/umext/floriculture/fact_sheets/greenhouse_management/bedfert.html

 

[Guest]

Update

Update

OK here we are two days shy of 7wks of flowering.

From the initial photos the following course of action was taken:

1) Flushed the soil with spring water
2) stopped the initial nutes
3) Removed all lower vegetation and die off > 50%
4) finished the flush with BioBloom and Sweet regular strength
(the lock up stopped or slowed uptake from the soil so a dillute mix of the above was applied as a "foliar" feed.)

After about a week it was clear the problem was indeed the fungus gnats and not the nutes.



Applied a generous application of OMRI listed soap and pyrethrin based insecticide to the soil tops only and lower bare stems(none on the flowers) and subsequently topped the soil with OMRI listed DE. Sticky traps were applied to the upper and lower regions of the grow to catch adults.

Another week and new calyx development and stretch were observed as well as some white fungus/mold so the "foliar" application was ceased, and the areas of white trimmed off. several days later the soil casing was mostly removed and then the remaining DE was worked into the soil tops.



Flushing has now begun with plain spring water and dillute Sweet. I don't know how much longer I can hold out, as the lower flower trichomes are starting to milk up.

 

[sproutco]

That bottom picture definately is showing too much nutes like ammonia nitrogen. The leaves are claw leaves plus don't they have necrotic white areas? Be careful adding sweet with just magnesium to your plant. There is a balance of 4:2:1 potassium to calcium to magnesium. If you raise magnesium levels, for example, you could cause a deficiency of calcium and then maybe potassium. Glad to hear your going to get a harvest.

 

[Guest]

Right on! Hopefully I'll get enough to last us through the next...and thanks for everyones help thus far. It's funny that my first couple grows were mindless with zero issues....other than shitty food and not enough light!!
It's time for the cabinet and surrounding areas to get a full shake down and cleaning. New caulk, new mylar etc.

Just started two White Widow from seed and two supposed Mango. The Mango's have sprouted and have been moved to a nursery area. As these progress I'll start a thread and link up. Check my gallery for some Sweet Tooth a friend left me...

 

[Guest]

Dried and cured and weighing in at just over 5oz! a surprising turnaround considering all the troubles. Thanks to Sproutco and everyone else for the input! Really would have loved to see where this went with no problems! I took a ton of pics but somehow lost em on my machine, I'll grab some more of the dried goods eventually. The smoke was rather sweet and tasty despite a weak flush. The plants were stressed so werent taking up as much H2O as the should have been. A VERY soaring high due to the clear trichs, but early cure attempts at a joint were unsucessful (wouldnt stay lit). It seems much more cured now and smells much more dank as well.

The Widows have exceeded the Mango variety seedlings but are showing a tad of a defficiency. I will get pics up soon.

EDIT TO ADD A PIC: These were some of the better tops, not much to look at but despite the hell I just went through I will accept with open arms and a clean pipe.

 

[Guest]

Alright then, so the two in the back are White Widow and the two in front are from seed from a pollinated Mango variety (supposedly, I didn't get to sample the smoke).


The taller widow shows a subtle deficiency of some sorts that I can't seem to match up...








The little mangos are quite interesting, check this node out...





PS sproutco you have the best avatars!

 

[Guest]

Just wanted to bump this thread rather than start a whole new one for a nute problem. Anybody got a hint of whats missing from these widows? I've heard white strains need more Mg than other varieties..or was it Mn?