Brown/rusty leaves; dry;spreading; please help!

[northernfligt]

So im still a newb. I apologize if this is an obvious question.

Light: 2 x 120w CFL ( 2700k + 6500k)
Medium: soil
Nutes: organic
Humidity: 40-55 % (working on getting it higher)
Temp: 23-27 celcius

- Lots of airflow
- watering every 2-3 days.
- Nutes once in 5 week from seed.


Problem:

The leaves on the smallest plants are turning crispy, brown/rusty from the tips in, then some yellowing appear, feels like sandpaper, different brown colors.

--------> look at pics.


Anyone have any idea?


Tnx ;D

 

[Highpotanoose]

What is ph of water/nutes? In and runoff

Guess without that info Phosphurus deff
Cannabis Plant and Pest Problem Solver - Pictorial

 

[northernfligt]

Ph 6,7 ish

What about fungus gnats?

Tnx for reply.

 

[Dan Ultra]

Is that 6.7ish or 6 or 7 ish? Big difference.

Do you see airborne gnats flying around your grow room? An effective means of detecting the presence of fungus gnat larvae is to insert 1/4 inch slices or wedges of potato into the growing medium. Larvae will migrate to the potato and start feeding within a few days. The potato slices should be turned over to look for larvae present on the underside.

 

[2clean]

Root rot,calcium def,too much potassium.

 

[northernfligt]

Thank you guys for responding.

CONCLUDED : SO ITS NOT BUGS

The problem got fixed on its own and I have no idea how, but it came back.

So they are still fading: Its hitting the midle leaves first, and climbing. Brown spots, light stems between the leaves.

So I really could not understand what was wrong. So I figured to try an other ph-tester.

End of long story:

The run-off ph was between 4-5.

The water they are getting are 8.0

After nutemix the ph are about 6.0-6.5

After reading 200 posts on the term "ph in soil". Ive gotten the idea that ph in soil (wich is given organical nutes) is not a problem, because it should equal it self out. This is because of the biological something, something..

So I started researching some more.

I realized that the soilmix Im using has a PH 5.6, instead of 7 wich Ive read is the ideal ph to start grow in when you are using soil.(???)


Q1 Do this mean that my soil (because of the biological "something something") will work it self down to a ph-lockout at 5.6 ?

- and should I change my soil?


Q2 Given the information resived, what is the problem here?



Thank you again, I love this forum

 

[Highpotanoose]

Pretty sure in soil you want 6.5 ph

 

[2clean]

Calcium. Root rot.

 

[northernfligt]

Thanks guys, I cant state enough how usefull this forum is.

2clean - i agree, think its calcium as well.

The ladies just got flushed, and I will wait untill they dry out and then add some calcium to the water and see what happens.


The girls are in secound week of flower now.



Q How long before they start getting better? (If the problem is fixed)

 

[2clean]

Thanks guys, I cant state enough how usefull this forum is.

2clean - i agree, think its calcium as well.

The ladies just got flushed, and I will wait untill they dry out and then add some calcium to the water and see what happens.


The girls are in secound week of flower now.



Q How long before they start getting better? (If the problem is fixed)

3-5 days.