Very cool to see them 3 all together and all around the same speed and size. The one with the ripples on the leafs a bit looks like a bit of calmag deficiency to me. I get it all the time at seedling phase dice they can't handle a high ppm and the coco grabs the calmag first. I do a weak foliar spray and that seems to pull them right out of it. But I'm over cautious and could be wrong. They look good.
Yeah, I think it's easy to get too twitchy about possible deficiencies or 'lock out'. I'm guessing it's mostly false alarms, so I keep everything super simple so I have minimal variables, which is another reason I want to try 5 different strains in the same reservoir to see for myself how sensitive they all are to the same nutrient. So far none of them are complaining about 500ppm. I am a little concerned about the slenderness of the stems at this stage though.
My Auto Glueberry OG came out with white tips which looked like nitrogen deficiency which made no sense because they don't really need anything at that stage, but it's just one of those things that just make it look strange and it's easy to draw too much from this.
... I ain't scared. Call in the banners!
Tough talk at this early stage, let's see if you need your brown trousers by the time the international judges fly in for the presentation ;¬)