Phosphorus deficiency?

Hey there.

I’m curious if my leaves are exhibiting the signs of phosphorus deficiency. They’re about 5.5 weeks into flowering. QCS O.G. kush feminized. Soil (FF OF) With a transplant from 3gal to 7gal a week before flower. I just started feeding them FF 3-part at half strength, as they looked happy and healthy feeding off the nutrients in the soil. 2 SF4000 LEDs in a 5x5.

Thoughts?

What makes you think you have P def? I don't see that in those pics.

The purple leaves and Google, I suppose.

Like I said in my original post, I haven't really fed them much since trasnplanting 6+ weeks ago. I added crab shell meal and FF Tomato and Veggie to the soil when I transplanted and they've been thriving thus far. I know I'm probably 2-3 weeks out from having to flush, so I didn't want to overdo it with the FF 3-part liquid nutrients.

They look fine to you?

hefflm said:

They look fine to you?

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They do. Let some others weigh in though. I admittedly have a hard time with colours sometimes, so I may be missing something. As I stated though, I don't see the typical signs of Phosphorus deficiency.

Ok thanks. Just wanted to get some eyes on it before I dose the shit out of them with a macro and end up tanking my first grow with 3-4 weeks left. haha

hefflm said:

Ok thanks. Just wanted to get some eyes on it before I dose the shit out of them with a macro and end up tanking my first grow with 3-4 weeks left. haha

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LOL yeah, definitely don't be overreacting and dumping a slew of stuff on the plants. That's usually the worst thing you could do.

Whenever you suspect a deficiency, first, the cause must be sorted out. If it's lockout or nutrient antagonism or something along these lines, adding more nutrients can compound the problem. If it is indeed a deficiency that isn't caused artificially, then you'd up the amount of that nutrient (or the bottle that nutrient is in) slightly. You'd then wait a couple to few days to see if the problem is getting better, or worse. Slightly increase until the problem goes away (or stops spreading).

Makes sense. It is definitely something I would've done 2 months ago.

I've been real cautious, as this grow started off really poorly. I was using tap water, not pH'ing, overwatering, underwatering... etc. I'm super tentative now, as I can see the light at the end of the tunnel. Especially with a flush nearing.

I'm 100% going to transition over to organics over the next few grows. Seems like more work upfront, but harder for an idiot like me to bungle. Also, the idea of flushing a 15 gallon (or even a 7 gallon) fabric pot makes me want to cry. I think the flushing in organics is less of a big deal? Obviously still in the VERY early preparatory phases of transitioning to organics (reading, watching videos, lurking in forums, talking to dreaded white guys working at grow shops).

There is definitely something going on. I am still leaning towards phosphorus.

Any one have thoughts about what is going on? Creeping up on 7 weeks... pictures attached.

What are your tent temperatures with the light on and off? How close are the lights?

If you are concerned about the purpling fan leaves it can be caused by many things. Genetics, and cold grow temps can cause purpling.

Phosphorus deficiency looks like this.

hefflm said:

There is definitely something going on. I am still leaning towards phosphorus.

Any one have thoughts about what is going on? Creeping up on 7 weeks... pictures attached.

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I definitely see P def in those pictures. What's the PPM or EC of your nutrient solution you're giving the plants? It could be that this strain is beginning to use up the nutrients within the leaves, or its a true deficiency.

When did you start counting your "7 weeks"? When you went to 12/12?

I started counting weeks when I flipped to 12/12. The short answer is I haven't fed them much at all, as I transplanted to fresh Ocean Forest a week before I flipped to 12/12. I've basically been watering them with CalMag'd RO water pH'd to 6-6.5 since last transplant. I added crab shell meal and FF Tomato and Veggie to the FF OF as amendments.

I gave them the bat guano and worm castings fertilizer (Big Bloom) once last week and some Big Bloom and Tiger Bloom yesterday. The reason I've been holding off is that 4/5 of my plants show no deficiency. This actually makes sense to me, as this is the only plant that didn't require a fair amount of defoliation. The rest were getting real moist in the center, so I went to town on the defoliation. The defoliated plants look "healthier" but their buds also look less weighty.I didn't want to start dosing them unless I really had to. Both feedings were at 1/2 strength.

So it sounds like I should actually start feeding this one at least. I thought the defoliation would make the plants need more nutrients than the plant that didn't get butchered, but perhaps my rationale was backwards.

Any other recommendations? Or just feed conservatively and wait?