Is this a nitrogen deficiency?

[ocgreen]

Hi everyone, I have some two week autos (Cream Cookies & Blue Deeam) going and could use some help.

While some plants are doing well as far as I can tell:


It looks like I have a mutant I will grow out in the name of science:



And oldest leaves going yellow for two plants:



Obviously most concerned about the yellow.

I did some reading and I lean towards nitrogen deficiency or light burn.

I say nitrogen burn because it says oldest growth will go yellow.

I say light burn because I just finished nuking my last grow under new quantum boards and still trying to dial in new lights.

Background
- RH, PH and temp staying in good range
- bucket temps floating from 19-24C
- 2x 250W LED quantum boards dimmed to 80w each 40" above
- 8x4 space
- Feeding flora trio according to GWE DWC schedule
- A few days ago I had a 3rd quantum board @ 80w & 40" going

At this point I raised lights to what must be closer to 50" just on the off chance it's light burn but would appreciate input from a more experienced grower.

What do you think?

[Canuck147]

Your plants look like they are hungry for something - 50 inches seems high to me. My cob is 36 for seedlings and then down to 24. My 300 vipraspectra is 24 inches above the canopy for seedlings.

To me they should be a darker green.

[ocgreen]

Hey Canuck147 thanks and a belated Happy Canada Day. I checked ppm and they were a bit low so I added some more nutrients. Sitting between 650-725 in all reservoirs now. And I moved lights back down to 38"

[Rwise]

I am not hydro but the yellow veins reminds me of sulfur deficiency, did it start in the veins and move out into the leaf?

[ocgreen]

It started on the tips and slowly started inwards. Will post some updated photos

[Sheesh]

They look a little hungry to me but I'm not a hydro expert. Are you using Cal-mg? Also, Hydroguard is good for roots and a healthy grow. Besides that, make sure your PH is in a good range and consider adjusting ph up and down to be sure that the plants are uptaking the different nutrients

[ocgreen]

I'm going to post some more recent pics. Hunger was definitely the issue for the Blue Dream. Probably a bit of the same for the Cream Cookies and either they're not bouncing back as fast or a bit harder to grow/genetics related.

[ocgreen]

I'm not using cal-mag or hydro guard at the moment. They're just getting the flora trio and will eventually get a PK booster and sweet candy during flower.

[ocgreen]

Thanks again to everyone helping to problem solve. Most looking much better after bumping up the ppms:





Nicknamed the mutant (bottom left) Rabbit Ears. Kind of excited to see where this one goes. Overall Cream Cookies seems to be a lot more sensitive and prone to mutations.

I made a lot of mistakes with some BlackBerry and Grapefruit but they're doing ok now:



so I'm trying to maintain positive vibe that they will all come back strong.