Leaves turning yellow/brown, decaying. What's wrong with my plants?

Details
This is my first grow. I use a large LED grow light, growing in coco coir, and feed them Fox Farm "Grow Big" liquid plant food (See contents in the image attached). I feed them filtered water and add nutrients every other watering. I water them every 2-3 days when the coir is mostly dried out. My plants are about 2 months old, still in veg state, and likely small for their age due to weak lights earlier on. I keep them on 16 hr either LED or a mix of natural lights and LED.

Problem
The bottom baby leaves dried up and feel off, no worries. Now a yellowing/browning along with drying out is happening starting from the bottom up. The new growth looks fine but the larger fan leaves are now getting this decay and I'm growing concerned. (See attached images) Happening for about 1-1.5 weeks now.

Possible Problems
I don't feel like i'm overwatering them, and the nutrient profile seems like what the plant needs to my noob understanding. Possibly root rot, pests, or under fertilization? Please shoot me some advice on how to correct this decay they are experiencing.

P.S. Based on how the plants look how much longer till flowering, or do I simply change their light schedule to 12 and 12? Been keeping a close eye but don't see any male/female signs just new growth in the joints.

Thanks!

Big one, your blurple light throws off any possibility of accurate symptoms, get a few shots under white light(normal light)and we will try to help.

Sorry about that, here's them under natural lighting. Most decay near the bottom, less/no decay at the top

CALCIUM! Possibly magnesium also. CALmag, CALi MAGic, are available at most hydro stores and of course online. You can always make some if you have eggshells. Definitely needs calcium. The yellowing of the base of your new growth is a big indicator. The damage to the fan leaves will not repair. If it doesn't look like the leaf is still beneficial, clip the leaf at the base if its stem.

Thank you, I ordered some supplements! In terms of the growing cycle do I just change the lighting schedule to induce flowering or do I just have to wait until its ready? I've been keeping it on 16 hours light 8 dark. If this is a question for another thread just let me know.

nathank said:

Details
This is my first grow. I use a large LED grow light, growing in coco coir, and feed them Fox Farm "Grow Big" liquid plant food (See contents in the image attached). I feed them filtered water and add nutrients every other watering. I water them every 2-3 days when the coir is mostly dried out. My plants are about 2 months old, still in veg state, and likely small for their age due to weak lights earlier on. I keep them on 16 hr either LED or a mix of natural lights and LED.

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I feed them filtered water and add nutrients every other watering.

You're in coco. Feed them every watering.


I water them every 2-3 days when the coir is mostly dried out.

You don't let coco dry out ever. Water daily once the plants are past seedling stage.


You're problem is that you're treating coco like soil. You need to treat it like hydro. 2 month old plants in coco should be at least 3 times that size.

For best results you will want to wait till she is ready. Typically they will show pre flowers between weeks 6&8 and of course any time past that. You can flip them before that but I would think yeild will be severely reduced. At 6-8 wells they start to mature sexually and flowering can be induced at anytime without stressing your plant.

Thanks for the tips guys. Gonna give them a few weeks to recover after I add the Cal-Mag and then trigger the flowering stage!

When to flower is 100% predicated on your space limits. The longer the veg the bigger the plant. Expect the plant to at least double in size when flower is flipped.

xtsho said:

I feed them filtered water and add nutrients every other watering.

You're in coco. Feed them every watering.


I water them every 2-3 days when the coir is mostly dried out.

You don't let coco dry out ever. Water daily once the plants are past seedling stage.


You're problem is that you're treating coco like soil. You need to treat it like hydro. 2 month old plants in coco should be at least 3 times that size.

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Here you have great advice. Dont overlook hia details, he is telling you 2 huge things here.

Xtsho does he need to transplant? I do not know how to grow in coco so i cant comment