One of three plants dying, please assist

I am a first time grower using a bag seed this time around so I get things right before moving up to a more sophisticated grow. I have three plants that are four weeks into flowering and one has started to look sickly within the past 4 days. The symptoms are as follows:

fan leaves are curling down and withering
leaves near buds are curling as well, which makes them appear narrow
bottom leaves are yellow

I am using Jacks classic at 1/4 strength every water. My other two plants are doing very well, and I have not been able to determine what the issue is

Here are some pics.

Thank you in advance for your assistance.

What is your PH? Could be overfert, but if you are on a 1/4 strength regimen, then I think more likely it is lock out due to a PH imbalance. Could also be a cal deficiency.

GS

is that in a room? it looks like you have alot of moisture in the air

valley grower said:

is that in a room? it looks like you have alot of moisture in the air

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Wholy crap...talk about moisture, I can't get my eyes off the moisture on those tits! lol
Not so sure about the moisture in the room, I don't see anything that points to that. Maybe I missed a clue...

GodSlave said:

Wholy crap...talk about moisture, I can't get my eyes off the moisture on those tits! lol

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haha thanx they r supposed to bounce but it wont do it on my avatar

Hey, this is off topic, but I noticed you have tin foil on the walls. When you upgrade your grow space, I would ditch the foil, it can make hot spots and burn. Many people use mylar, I have also in the past, but I now prefer panda film. It's much easier to clean up, and pretty much doesn't wear out like mylar. Just my 2 cents...

valley grower said:

haha thanx they r supposed to bounce but it wont do it on my avatar

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Thats a real bummer, I could have spent more time fixated lol.

You have a pH imbalance, Phosphate deficiency, and what looks like a Nitrate toxicity.

Thank you for the pointers, I really appreciate it.

If I am understanding correctly, I first need to measure the PH. Most likely I need phosphate and to reduce the N. To correct this issue, should I flush and then supply the phosphate in amounts dependent upon the PH testing?

Thank you for the additional information. Every bit helps.

Hey, this is off topic, but I noticed you have tin foil on the walls. When you upgrade your grow space, I would ditch the foil, it can make hot spots and burn. Many people use mylar, I have also in the past, but I now prefer panda film. It's much easier to clean up, and pretty much doesn't wear out like mylar. Just my 2 cents..