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Mooons- High heat and low RH, possibly too intense lighting are all in play here,... any combo of low RH, high temps, and strong breezes will cause the curling, pale color; overly strong lighting can cause the color loss as well, or worse-- how high up is that new Mars unit? That's a big jump in output! Seedlings need to start out with less intense lighting, so about 24" from tops is fine,.... how's the soil moisture? Seedlings want nice even, consistent moisture, not always easy to keep in larger pots at this stage,... a sprayer is handy for spot watering around the seedlings often as needed, but in fabric pots things will dry faster all around as well, so make sure the outer, deeper areas are still well moistened,... when they get roasted, transpiration gets shut off to preserve water, and so transport of nutrients slows way down as well, cause color loss, even deficiency symptoms,... some of the little ones look pretty rough, but savable,... get your temps' down as best can for now, and keep that RH up over 40% at least,...no Ca or Mg defc. symptoms I can see,... The soil pH is a concern as well, so check that to see if it's off, and let us know what it is...
