Is this a potassium deficiency?

Trying to do my own sleuthing before I just come here and post pics asking for other people to tell me what this is....but here I am posting a pic and asking to check my findings, so I guess it's all the same anyway.

According to the chart, this looks like a potassium issue. Am I right? It didn't look like this yesterday when I watered.

Auto Diesel - Day 30 of flower - CocoLoco medium - Dr. Jimz Nutes - 20/4 light schedule - 80deg - 50RH - 18" light from canopy

I don't think it's light burn...my lights are at 18" so not even as close as the recommended 12".
I don't think it's magnesium...I am adding cal/mag at every feeding.
I don't think it's PH...I PH the water to 6.2-6.5 at every feeding.

Anyone?

I'm no pro but I think it looks more like a cal/mag deficiency to me.

It looks like it's been well fed. Maybe too much food. Be careful adding anything as the problem could be from too much. Many of the issues people have are from nutrient antagonism caused by overfeeding. Adding more can make things worse. Many of these issues manifest themselves midway towards later in flower when people add too much additional P&K from using bloom boosters.

According to that picture you posted your leaves resemble a Potassium excess rather than a deficiency. It looks like it's starting in newer leaves and the edges are not burned. I'm not a big fan of those deficiency charts and photos but if you go by them then you're plant obviously resembles the description of Potassium excess and not deficiency.

CptTripps said:

It didn't look like this yesterday when I watered.

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How often are you watering it? Are you letting the soil dry out enough between watering?

That came on real fast, what is your pH running? Do you bottle feed or is this an organic soil that may have exhausted it's supply? Just reread and saw the cocoloco so I assume you are not bottle feeding?

Renfro said:

How often are you watering it? Are you letting the soil dry out enough between watering?

That came on real fast, what is your pH running? Do you bottle feed or is this an organic soil that may have exhausted it's supply? Just reread and saw the cocoloco so I assume you are not bottle feeding?

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I think we figured out the issue in my grow journal. I may be over-feeding. The guy at the hydro store had me feeding with every watering, and I guess that's a no-no. So I've been over feeding this whole time.

I water every 3-4 days for some plants, and every 1-2 for the thirsty girls in flower. I wait until the pots get really light, and sometimes the leaves just get really tired and the plant tells me.

So I guess from other's comments and it's a combination of the plant getting older and closer to being done, and the fact that I've been feeding with every watering.

CptTripps said:

I think we figured out the issue in my grow journal. I may be over-feeding. The guy at the hydro store had me feeding with every watering, and I guess that's a no-no. So I've been over feeding this whole time.

I water every 3-4 days for some plants, and every 1-2 for the thirsty girls in flower. I wait until the pots get really light, and sometimes the leaves just get really tired and the plant tells me.

So I guess from other's comments and it's a combination of the plant getting older and closer to being done, and the fact that I've been feeding with every watering.

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I told you that in the 4th post.

Growing cannabis 101:

Don't listen to the guy at the hydro store. You don't listen to a car salesman tell you how to drive a car do you?

One last question on this...

Should I remove the yellow leaves? I don't think they're doing their job anymore. More posed up last night. I watered this morning, and will continue to only water a few more times before feeding again, but what to do with the yellow leaves. I don't see them coming back, as they're brittle now.