Deficiency or overfert, knowledge required?

[SupaC]

Hi there fellow growers.
I'm seeing some funky symptoms in week 5 of flower.
Medium : Ts4 ; buffered peat based substrate, with 20% perlite.
Ph input : 6.2
Runoff : 6.1- 6.3
Ec : 1.7
Ec runoff : 1.5 average
Additives: Fulvic acid at 2ml per liter.
Co2 : 1200ppm
Temps: 25 - 27 Celsius
Rh : 55- 60

Watering frequency: Once a day to run off.
Deficiency or overfert is happening in the lower fan leaves which are curling up .
Possible Mg Deficiency but no interveinal chlorosis, leading me to wonder if it's an overfert.

I appreciate any comments.

 

[Aqua Man]

Everything you listed looks good. Whats the pot size? How much are you watering per event?

Do you run a burner or bottled co2?

 

[Aqua Man]

Also how is your air flow under and through the canopy?

So you have any mobile temp/humidity gauges you can place in these areas for readings?

 

[SupaC]

Hiya AM .
Thanks for stopping by.
Pots are 10l fabric and the co2 source is bottled.
Air movement above and below is acceptable , running HAF's in the ceiling and oscillators on the walls.
I only have 2 Rh sensors, not mobile due to lacking budget, in the room. The HAF' s are very efficient at keeping things constant.

 

[Aqua Man]

Hiya AM .
Thanks for stopping by.
Pots are 10l fabric and the co2 source is bottled.

They maybe getting to dry by the time you water. Try increasing to 2 times a day

 

[Aqua Man]

Are you venting the room at night?

 

[SupaC]

I am indeed venting at night brother.

 

[SupaC]

I am indeed venting at night brother.

Regarding the 2 x a day watering.
I'm actually a coco grower by experience.
This peat based substrate was an unfortunate choice because I'm unfamiliar with it , however there was a coco shortage at the time.
There is very little literature regarding this substrate and I have been using promix guides to get me through, as promix is also peat based.
It's taking at least a full day for the pots to dry out after watering to 20% run off.

 

[SupaC]

I strongly suspect that my watering is off , but this substrate seems to love holding on to water.
Next time I'll add more perlite.
I wonder if shorter watering events throughout the day might oxygenate the pots , as with coco. Just concerned about the old over watering.

 

[Aqua Man]

I strongly suspect that my watering is off , but this substrate seems to love holding on to water.
Next time I'll add more perlite.
I wonder if shorter watering events throughout the day might oxygenate the pots , as with coco. Just concerned about the old over watering.

See if something here catches your eye. But i think they are drying out to much between watering. I did pear in 2 or 3 gal and i also had to water more than once a day to my surprise.

Marijuana Watering, how media, pot size/shape and environment affect it

Discuss different watering methods for growing your own weed from seeds. Our community members give helpful tips on how pot size and material, as well as environmental factors affect growing cannabis.

www.thcfarmer.com

 

[SupaC]

Just finished that thread of yours thanks for posting.
When you were watering peat 2x a day were you letting it dry out or just before?

 

[Aqua Man]

Just finished that thread of yours thanks for posting.
When you were watering peat 2x a day were you letting it dry out or just before?

Before i watered at lights on and then again about 4 hrs before lights out in flower

 

[Aqua Man]

I should add just out if caution but im sure you know… none of the damaged leaves will improve but it should stop getting worse in about 4-5 days

 

[Aqua Man]

If it has been underwatered the peat may become hydrophobic… so maybe grab a random sample and check.

If so you may need to scratch up the surface and pokes some holes top to bottom. A couple other ways also but just check to be sure they are not hydrophobic first

 

[SupaC]

I'll look into this and just throw in some dish soap as a surfactant.