other than somewhere in northern mexico i dont really know. if youre thinking genetics, im skeptical only because im using the same seeds as a friend of mine who has no problems like this at all but he does have a well and filters his water as it comes in to the house. that and i have germinated just a shitload of seeds in the past few months. as long the ph of the solution is between 6.2 and 7 they germinate every time and start growing really nice. the first time they get watered, and ill admit the first few i was watering too often but i corrected that and they still have the exact same issue at about 2 weeks. the more wet the soil is the faster it happens. i have used just about every soil i can find...and it being winter that doesnt leave much. so far foxfarms ocean forest has worked the best. seed starter, light warrior doesnt matter as soon as they get water they start getting the signs of yellowing at the tips and edges. let them dry long enough and that seems to back off they green up hit them with water again and thats just water i havent had any get to the point where i can add nutes yet, and the yellow starts to show again. everything seems to point to the water and from everything i have read chloramine appears to be the most viable culprit. ill have a better idea after i do some run off checks to see if the soil ph is creeping up like i think it is.