Hey team! Wondering if you could help me out here. I’m seeing a bit of a concern early on and I’m hoping you can help me determine the issue. Here is the info.
All autoflowers. Left to right - Critical, Cheese, Dark Devil, Six Shooter.
336W LED at approx 30” above canopy.
5 gal fabric pots
Coco/Perlite
Gaia Green dry amendments. 444-284 70/30 at 3 tbsp/gal.
Week 3.5 - LST performed at week 3.
pH always between 6.5-6.6 so far. Been steady with this and calibrate my pen every week.
I am starting to see what looks like either a nitrogen burn or light stress. Thing is, my lights are at the correct height according to the manufacturer, though I just raised them another couple inches. That’s all the room I have left. As far as I knew, organic nutes don’t cause burn or are less likely. I am not really sure what to do here. Your help is highly valued and greatly appreciated.
Sorry. Temp is 22-26C and RH is 50-60.
Well, let’s see, not an auto or coco guy but I’ll tell you what I see, you have the wrong ph for coco, which should be more like hydro ph 5.6 to 5.8. Your plants have started flowering, they need bloom nutes at this point, if staying within the Gaia line, you should move to the Gaia Power Bloom. Also coco is very calmag hungry, are you providing CalMag? If not, need to do so.
Ok cool. So, I tried the lower pH on a previous grow and they barely grew at all. I have read lower pH is best for coco, but I have found the higher pH works pretty well with this particular mix. Perhaps it’s the nutes that lower the pH to the right spot…? I have a cal mag supplement, I haven’t used it mainly because the symptoms don’t seem to match up with calcium deficiency from my online research. If I add it, could it cause any harm? Lastly, when I re-amend, I plan on going with the power bloom for sure 
Yeah I don’t see a calmag problem in the pics but seems coco users go thru a lot of calmag, maybe your water source has a decent amount of it. I’d get some bloom nutes and feed them up with that, sometimes a good feeding is all it takes to green them up a bit.
Yeah. The plan was to top dress them in a week or so. I suppose it wouldn’t hurt to do it a little earlier as these girls are growing big, fast. I’ll add a little bit of calcium to the top dress to be sure. You think if I go half-strength I should be safe? Last thing I want to do is burn em. Though I’ve read with dry amendments, it’s less likely they will burn as the plants take what they want, when they want it as opposed to bottled nutes that are forced in to the roots when watering.