Brown & yellow leaves - First time grown

G

GandalfGreen

Active Member
Hey people of :420:! :D

I have started my first grow and am paying great attention to how my plants are doing. A few days ago I noticed some brown/yellow spots starting to develop on the leaves which I'm not sure (using the deficiency guide) what it is. Could someone take a look and tell me what they think? The spots seem to keep developing and not receding.
For more detailed information about my grow you can check out my grow log.

But for now, here's some quick information:
Strain - The Doctor
# of Plants - 3 (2 x The Doctor, 1 x Arjan's Haze #3)
Grow Type - Soil
Bucket Size - 1 gallon
Grow Stage - Seedling
Light - Mars Hydro Reflector 192 LED panel (420W@110v; 410W@220v, PAR of 1200umol at 18 inch)
Nutrients - None yet.
Medium - Biobizz All Mix
PPM - not measured yet
PH - 6
RH - 30-40%
Room Temperature - 80-86 fahrenheit (27-30 celsius)
Room Square Footage - 1.2m x 1.2m x 2m
Pests - None Known

Here are some pictures:
2016-07-05_07_35_06.jpg

2016-07-05_07_35_17.jpg

2016-07-05_07_35_29.jpg
 
re: Brown & yellow leaves - First time grown

Your soil looks wet. Hopefully that is just a coincidence with the timing of the pictures.
Your temperatures are high and your RH is way low. Some of what I'm seeing is probably heat stress. The plants can't transpire the way they need. You need to try and bring the temp's down, and try to about double that RH.
IMO, these things are more important right now than any possible deficiency. I don't use Biobizz but it sounds like it should have you covered this early on. Focus on correct watering and environment.
 
re: Brown & yellow leaves - First time grown

Hi Gandolf,
Can't be sure by pic but it's either:

Burns from water drops on the leaves under the light..... or

Your water. PH issue or additives from municipal water. Doesn't matter....... Get a Brita water pitcher and give them filtered water. My city water ph fluctuates constantly plus they often add copper and sulfur- almost killed my girls till I discovered this easy fix.
:peace:
 
re: Brown & yellow leaves - First time grown

Oh- and no need for co2 supplementation till late flower. Babies are fine in room air.
 
re: Brown & yellow leaves - First time grown

Flower Child said:
Hi Gandolf,
Can't be sure by pic but it's either:

Burns from water drops on the leaves under the light..... or

Your water. PH issue or additives from municipal water. Doesn't matter....... Get a Brita water pitcher and give them filtered water. My city water ph fluctuates constantly plus they often add copper and sulfur- almost killed my girls till I discovered this easy fix.
:peace:
Click to expand...
It could be burn from water drops as I foliar feed them every 3-4 days. Although the lights themselves are 18 inches above the plants. As with the pH, I keep a steady pH level of 6.0. My tap water is around 8.2 pH without any additives and I get it down with some pH- solution.
I'll maybe stop foliar feeding for a while and see how that goes. I've also ordered an oxygen pump with a water stone. I'm going to get a big container filled with water and run the pump constantly to add a good amount of oxygen to the water.

Thanks for your link as well, I'll check it out!
 
re: Brown & yellow leaves - First time grown

Major PITA said:
Your soil looks wet. Hopefully that is just a coincidence with the timing of the pictures.
Your temperatures are high and your RH is way low. Some of what I'm seeing is probably heat stress. The plants can't transpire the way they need. You need to try and bring the temp's down, and try to about double that RH.
IMO, these things are more important right now than any possible deficiency. I don't use Biobizz but it sounds like it should have you covered this early on. Focus on correct watering and environment.
Click to expand...

Yeah I just watered a few hours prior hece the wet soil. What temperatues would I be aiming for? It's just that I've read a lot of conflicting information. I've read Ed Rosenthal's book (Marijuana Grower's Handbook) and came across this chart:
page272.jpg


I don't have exact measurements handy right here but it has a PAR of 1200umol at 18 inch. I'd say that's quite bright. Don't you think that the plants could thrive at temperatures around 80-86 Fahrenheit?

Regarding the humidity, it's something I'll look into to see if I can get it up easy somehow, thanks for the pointers! :)
 
GandalfGreen said:
Yeah I just watered a few hours prior hece the wet soil. What temperatues would I be aiming for? It's just that I've read a lot of conflicting information. I've read Ed Rosenthal's book (Marijuana Grower's Handbook) and came across this chart:
page272.jpg


I don't have exact measurements handy right here but it has a PAR of 1200umol at 18 inch. I'd say that's quite bright. Don't you think that the plants could thrive at temperatures around 80-86 Fahrenheit?

Regarding the humidity, it's something I'll look into to see if I can get it up easy somehow, thanks for the pointers! :)
Click to expand...

Yes - I think plants can do quite well at 80-86. The lower end of that spectrum is ideal. In fact, I believe MJ is happiest between 78-81. The key is the combination of temperature and humidity. They work together to create the vapor pressure deficit the plant wants in order to transpire (breath). I think this chart shows the relationship as well as anything. The goal is to "go for the gold". As you can see when the temperature is 90F, you want the RH up around 80%. When the temperature is 75F, you want the humidity about 65%. There is no reasonable temperature for cannabis where plants thrive with humidity down in the 30%-40% range. You'd need to be growing in 50's. These are ideals. It doesn't mean you can't grow outside them.
RH_chart1.jpg
 
Now that makes a whole lot more sense than it did before :D That's an awesome chart which I will definitely be stealing from you haha! Time to go get me a humidifier then.

The water that I put in the humidifier should I pH it as well? Since the plants will be foliar feeding themselves with it.
 
GandalfGreen said:
Now that makes a whole lot more sense than it did before :D That's an awesome chart which I will definitely be stealing from you haha! Time to go get me a humidifier then.

The water that I put in the humidifier should I pH it as well? Since the plants will be foliar feeding themselves with it.
Click to expand...

I wouldn't bother adjusting the PH of the humidifier. It won't make any difference to the plants.
 
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