HELP! Any idea what could cause this in seedlings?

[Rcass]

Please Help any guidance would be very appreciated!

Hi folks, newer member, first time posting. Few years dirt experience, newer hydro (less than two years). Hydro is a bit more involved and quite frankly can be a pain in the ass.


I have been running into this vein yellowing issue quite a bit recently and I’m going a little bit nuts! My initial guess was a deficiency (maybe cal, mag, iron or nitrogen). After going through my prep notes all seemed good and my ppm (EC) was in my desired range (perhaps a little higher than normal with the CalMag but there isn’t any evidence of nute burn that I could tell). Next guess was LED stress. I measured the PAR value and was low (150 PPFD). Here are some data points:

1. RDWC/aeroponics hybrid
2. PPFD 150
3. Bloomspect S1000 LED (qty 4/tent, 1/plant)
4. 32” from plant at 25% power
5. Humidity 55%
6. air temp 77-81
7. GH flora trio with calmagic ( I add cal/mag as I use distilled)
8. EC 0.7-.0.9
8. Strain LSD 25 Auto
9.water temp averages 72 with hydrogaurd
10. PH target 5.8 , daily range 5.6-6.0
11. Tent(s) Spider Farmer 5x5x7
let me know other specs you may need


let me know if cannot zoom in enough and I can take closer shots.

Cheers folks

[Rcass]

No advice from anyone? Am I posting incorrectly?

[3Berries]

What happens as they continue to grow?

[Rcass]

Thanks 3berries for the response. They are at about three weeks in since germination. The thing is they get to about the size that is shown in the pictures I attached and then basically just freeze. Almost reminds me of shock of some sort. My only thought is that the LEDs are burning them but as I measure the par values I don’t see anything that would raise a flag. The pause or freeze that I mentioned may be the plant focusing on building a root structure and that is where it’s energy is going. I keep lights 18 to 36 inches away

[3Berries]

Is it getting any micro nutrients like copper, zinc or manganese from the nutes?

[Rcass]

Yes I am using the GH flora trio with, calmag and rapid start including iron. I use calmag throughout my grow, I use only distilled water

[GroBuddy]

I dont grow this way but I dont see any water temp information. Go post in the hydroponic section of grasscity Forums, good luck

https://forum.grasscity.com/forums/h...c-growing.690/

[Rcass]

Thanks grobuddy will do. My water temps stay at 70-75 with hydrogaurd.

[GroBuddy]

Not gonna lie i dont know anything about growing like that. Just give the same post add that and may take a bit, but someone will be along to help I'll tag a couple people if no one comes after a while.

[Rcass]

Just posted GroBuddy, cheers!

[Rwise]

Hit the link at the top of this page "Plant Problems" and look at sulfur def.

https://www.growweedeasy.com/cannabis-plant-problems/sulfur-deficiency