Calcium Deficiency? Phosphorus Def? Orrr?

[grown6hunnid]

What's up icmag crew, I'm on my third run ever, first time doing photos (these are fems) and I'm running into a bit of an issue kind of late into flowering, week 6/7. I'll include pictures, but the top fan leaves on one of three of my plants form brown splotches, not small dots but like pretty large brown spots, then the tips eventually curl upwards and begin to die, until the whole leaf is pretty much crisped. It is also happening on a few fans on some secondary colas but not as severe yet. I've also noticed how with the top fan leaves, when they start developing these symptoms, they usually do it in pairs by node (both fans on that node die together). I'll give y'all my setup and nutes and what not to give y'all an idea of what I got going:

4x4 grow tent
3 plants
400w actual (viparspectra 450w, sunraise 1000w, and optic 1)
Active air 4 inch exhaust fan w/ carbon filter
4 clip on fans for air flow
3 gal fabric pots
Roots organics original soil; I added: dolomite lime (my tap here is soft) and a layer of endo myco
Watered tap that I let sit for 24 hrs
Ph should be near 7 b/c of dolomiteI don't check it
Day temps: 74F - 82F Night Temps: 68F - 72F
Humidity: 45%-50%

I don't think it is heat stress because the girl behind her is far closer to the light and the very end of her leaf tips are only just starting to slightly curl and burn. I am planning on chopping at 8 weeks so they only got about 2/2.5 weeks left. I also check the trays they're sitting in for stagnant runoff and maybe roots grew threw the fabric but no roots or run off. I gave here a tsp of dolomite yesterday so in about 6 days I should see if it was a cal deficiency, but now I'm thinking phosphorus because of the size of the splotches and the progression of whatever this is. I do have some guano for P, but if I'm gonna be chopping in 2 weeks should I just ride it out and let them do their thing. Buds do seems to be still forming nicely, frosting up okay, smell pretty nice, her leaves are just telling me something's wrong and I need to figure it out. Hope these pictures can help anybody diagnose this, thanks in advance anybody who comes to the rescue.

 

[troutman]

Below each pic in your photo album is a BB Code.

Copy and past that into your post and your pics will show up there.

 

[grown6hunnid]

1st pic is of fan leaves from the main cola I pulled off yesterday because they were just fried
2nd pic is of the top cola today, whole new set of leaves started crisping and curling up
3rd pic is another shot of the main
4th pic is a shot of some of the lower fans showing signs
5th pic is of another lower fan so show a good look at those brown spots

 

[packerfan79]

Hard to tell anything in that light. I would say get some ph strips, or drops, and stop guessing with lime. Ph is the most overlooked factor for new growers.

What are you using for nutrients?

Is this the first time you have had this problem?

Did I make any changes since previous grows?

I would try ro water to eliminate that factor. Letting your water sit will help with chlorine and chlorimine, but it won't help with the minerals in the water.

Temperatures are fine.

 

[grown6hunnid]

Yes, this is the first time I've had this problem and the others look just fine. I have ph strips and the ph of my tap is 6.5. The only thing I have changed is adding the cob and the sunraise. My nutrients were already in the soil, the roots organics original, so I mixed the appropriate dose of dolomite in the soil before planting and they seemed pretty healthy up until a couple days ago getting plain tap. I also only have dry amendments that I would top dress with for nutes.

 

[grown6hunnid]

I'm gonna switch over to ro though, didn't know that about the minerals

 

[packerfan79]

I'm gonna switch over to ro though, didn't know that about the minerals

I think your soil is running out steam (nutrients). LEDs need higher nutrient requirements in some cases. I have no experience with built soil . I am a coco guy. I like controlling the nutrient inputs. I would consider keeping some nutrients around for situations like this. General hydroponics is dirt cheap, Veg and bloom, or megacrop , dyna gro.

 

[grown6hunnid]

That's what I was thinking too, they were vegged for a month and this is about to be month 3 so the soil's probably pretty leeched. Nowhere to get any flower supplements near me so I'll have to order that, so I'll just have to let her go til finish and see how she does. Thanks for the help though

 

[LostTribe]

I'm gonna switch over to ro though, didn't know that about the minerals

That doesn't mean jack squat. See previous posters recommendation and test the soil/medium.

Those dead leaves in the first pic look like a phosphorous deficiency which has ZERO to do with RO or not.

 

[LostTribe]

I think your soil is running out steam (nutrients). LEDs need higher nutrient requirements in some cases. I have no experience with built soil . I am a coco guy. I like controlling the nutrient inputs. I would consider keeping some nutrients around for situations like this. General hydroponics is dirt cheap, Veg and bloom, or megacrop , dyna gro.

I think its a Phosphorous deficiency, but would test the soil or whatever medium PH to begin with.

When in doubt FIRST refer to this thread in the Infirmary. Check your PH.
https://www.icmag.com/ic/showthread.php?t=11688

I've never had plants show that due to lack of NUTES only to PH.
LT

 

[troutman]

I have ph strips and the ph of my tap is 6.5.

Your pH is perfect. I read that 6.5 is the best for phosphorus availability in soil.

 

[RoostaPhish]

Just an fyi. I just had issues with bad test strips. A whole roll. They were giving false readings. I mean WAY off. Verified by pen and drip tests. First time I have experienced this.

 

[f-e]

pH of the tap isn't particularly relevant.

It's P and is best fixed by chemical means. Signs like this mean significant stunting has probably taken place.

P is a transport element, and typically used in high quantities when banging the weight on.

Consider a PK boost. One where it's not all about the K. Perhaps 0-10-10 or 0-13-14 but not 0-12-20 as your plants have shown it's P they want.

 

[mexweed]

probably rootbound with that veg time and pot size, generally never less than 5 for organic soil

 

[Ratzilla]

I second that it would be helpful if you turned that LED light off before taking pictures what with the purple hue.
But in saying that i also think it is a P deficiency.
In organic growing it is the mycorrhizal fungi that is responsible for MOST P uptake.
KNOW THIS
If adding LIQUID P of any kind that this will hurt the fungi population.
It is best if wanting more phosphorus to add in small amounts of nutrients that have phosphorous in small ratio's.
I think of the fungi being responsible for uptake and the harming of the fungi as a true paradox in organic growing.
High ratios of P and any kind of liquid P will do harm to the fungi so beware of this.
I am also of the school of thought that in organic growing that the plant is in charge.We as gardeners only set the stage in making sure the parameters are where they should be.
I say this for any thing you do now with but 2-2.5 weeks left might be ineffective.
My favorite P solution at this stage would be something like 0-4-0 bat guano or 0-3-0 soft rock phosphate these are both fast acting low ratio made into a tea.
Next time around keep in mind that doing no harm to the fungi being they are the main player in P uptake.
Avoid adding P in any liquid form or adding high ratio P nutrients I prefer to keep the p ratio at a 8 or under or this will surly hurt the fungi.
Once harmed by liquid solution of P a grower can only keep doing that (adding P in liquid form).
I think of this paradox as TV diners and not home cook meals.
It's some times hard to keep things simple when some times they are not.
Ratz just trying to pass on knowledge.

 

[greenspiritz]

Purple petioles and dark/blueish leaves would certainly indicate a Phosphorus deficiency. You say she's been in the pot for a while?

I'd hit her with some PK Boost at the stage you're in. I'd also suggest purchasing an EC & PH meter along with calibration fluid.

Such valuable tools for the garden, and help take the guess work out with half a solution to any problems that may arise in the future.

Your plants still look super though, good luck taking her to the finish line

Green