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

Ok lots of posts on how to water plants. So I thought I would put together a thread on how different factors contribute to different results that ppl see. This will be a long read based on my personal knowledge, opinions, research and others work to consolidate information for our members. I'm...

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.