Plant has brown spot on leaf, seems dry too. Light tips on new growth.

[Illegal Wonder]

Hey I'm going through my first grow. I noticed a dark spot yesterday on one of my lower leaves, today its a brown spot. It looks like the edge of the leaf is drying and getting brown... I also noticed today the new growth tips look lighter

 

[Sativied]

I wouldn't worry too much about that little brown spot by itself, but they do seem a bit light green. You'll have to provide some more details though, what lights at what distance, soil, any nutes yet, do you measure/adjust ph? (I'm guessing the last one is the cause, maybe over watering, but without more details it's not much more than a guess).

That said, I sometimes have a lighter and seemingly weaker plant amongst my usually 5-6 plants even though it gets the same water+nutes+ph+temp etc, and it always turns into a dark green adult.

 

[Illegal Wonder]

I have 4x 42w CFL's at 3'' from the plant. I'm using Coco coir as a medium, I have given it some BC grow nutes. I've measured the PH but haven't adjusted, ph is at 6.5 in the coco. I don't think its over watering. I transplanted about 2 weeks ago and have watered twice since the last being 3 days ago, and I did give it some Nutes at 1/4 strength. Temp is between 21 c and 23 c

 

[Sativied]

Ok, first thing you should do is raise the temp to 25-28c during light on, and up to 10 degrees less during light off (18-20c). Even if that means turning off/lower a fan. Your plants will thank you for it (much better photosynthesis at 28c than 21-23).

I'm not familiar with growing on Coco coir so I would await some more replies but giving it some more nutes should darken those colors again. If you can exclude watering and root issues that is. But do raise the temp, it's not really optional to have good temps.

 

[Illegal Wonder]

I have it in a closet, i felt it was getting to hot inside so i've had the door open with a fan blowing in. I'm wondering how to raise the heat and not over do it... Also I'm worried about Nute burn, was kind of wondering if that's whats been happening.

 

[Sativied]

If it were nuteburn it would go from light to yellow to burn, usually at least at the tips as well. But if that is from nute burn it looks like it has outgrown it already.

Does the closet have one or more intakes and an exhaust?

 

[Illegal Wonder]

No, I haven't gotten anything like that hooked up yet. I jumped into water before learning how to swim here, threw 2 seeds I found into dirt from my front lawn and they grew... I have a ceiling fan for a bathroom that I can install as an exhaust, and looked up a decent DIY carbon filter. Should I put the fan in the ceiling or in the wall closer to my plant, and what should I do for intake? Would I just go with another bathroom fan, or is there a cheaper way to make the intake?

 

[Illegal Wonder]

It looks like the edge's of the bottom leaves are getting brown and wilted now. The one has gotten quite a bit worse over the last day...

 

[Sativied]

I use a large oversized PC fan for active intake, and a passive intake next to it. Active intake isn't as important as active exhaust, which is kinda a necessity in a closed environment. Exhaust should go ideally at the opposite side of the intake. Intake low, exhaust high.

Yard/lawn soil from gardening shops often isn't very suitable for mj plants, especially small ones.

Not sure why you are not getting more replies... maybe a picture of the updated situation can attract some more repliers. And have you changed anything since the previous picture?

 

[70's natureboy]

They do look pretty light green.. They are small but I think they are ready for a light feeding.

 

[Illegal Wonder]

I use a large oversized PC fan for active intake, and a passive intake next to it. Active intake isn't as important as active exhaust, which is kinda a necessity in a closed environment. Exhaust should go ideally at the opposite side of the intake. Intake low, exhaust high.

Yard/lawn soil from gardening shops often isn't very suitable for mj plants, especially small ones.

Not sure why you are not getting more replies... maybe a picture of the updated situation can attract some more repliers. And have you changed anything since the previous picture?

I picked up a smaller ceiling fan for an intake, hooked both fans up today. I didn't have much option and had to put them both on the same wall but did put the in low and the out up higher

 

[Weliveinapolicestate]

https://www.rollitup.org/marijuana-plant-problems/488004-guide-nutrient-deficiency-toxicity.html

 

[Illegal Wonder]

https://www.rollitup.org/marijuana-plant-problems/488004-guide-nutrient-deficiency-toxicity.html

thank you!

 

[Weliveinapolicestate]

I think when you join this site it should just send you straight to that thread. It's the most useful thread I've ever found on this site. Hope it helps. Peace

 

[Illegal Wonder]

My plant seems to be looking worse (to me). The leaves look pasty and like they lost the shine they had. I watered last night without nutes hoping to flush out the salts and any excess nutes.

 

[sohighifly]

Silly question but what is the kelvin rating of your CFL's.I am only taking a stab and offering opinion because I am not an expert,but when I first started mine were lime green like that and noticed my MH was 4200k two days after I switched to 7500k they looked great.Again don't take this as your problem,just something to check.

 

[Illegal Wonder]

Silly question but what is the kelvin rating of your CFL's.I am only taking a stab and offering opinion because I am not an expert,but when I first started mine were lime green like that and noticed my MH was 4200k two days after I switched to 7500k they looked great.Again don't take this as your problem,just something to check.

My kelvin for each bulb is 2700k, It is impossible to find 42w cfls any higher than 2700k in my city but I was told 4 of those is better than the 5 26w 6500k I had before. the 3000k and 6500k only come in 26w... I'm planning on switch to MH now that I have an exhaust system hooked up, but my broke ass needs some money for the bulb... What price range should 400w MH bulbs be in? The ones I saw were $50, and I'll have to wait till next week to pick one up.

 

[Illegal Wonder]

My leaves seem to be cupping a bit, I don't think its heat stress though...

 

[Nizza]

coco coir requires cal mag every feeding. there may be enough in your tap water but to be sure get some and add it in progressive amounts, starting at 1ml/gal and progressing to 5ml/gal. also coco has no nutes in it so tap water may let it grow a little but when it starts to foliate gradually bring nutes in at 1/4 dose or 1/8 dose. every week give it fresh water and get it to runoff to leech salts off the roots. to avoid salt buildup don't allow it to get too dry and also remember not to over-water, this will cause moisture stress.

 

[Illegal Wonder]

coco coir requires cal mag every feeding. there may be enough in your tap water but to be sure get some and add it in progressive amounts, starting at 1ml/gal and progressing to 5ml/gal. also coco has no nutes in it so tap water may let it grow a little but when it starts to foliate gradually bring nutes in at 1/4 dose or 1/8 dose. every week give it fresh water and get it to runoff to leech salts off the roots. to avoid salt buildup don't allow it to get too dry and also remember not to over-water, this will cause moisture stress.

Cheers man, this is exactly what I needed to be told. I'm off to get cal mag today, and I hydrated my coco with nutes and have been giving them every other feeding. I also mixed worm casings into some water and sprayed the leaves a bit.

Also I just watered last night, how should i go about giving the calmag to my plant, wait till next watering?