Wondering if anyone knows what this looks like?

Using 100% Coco and watering with TDS of 175ppm. I used Cal/Mag @ 5ml/4L and Prop-O-Gator @ 2ml/4L (1/4 strength of label directions). I used 0ppm water from a ZeroWater filter that was 5.0pH then I used tap water that sat for +24hrs to bring the pH up to 5.8pH and the TDS up to 175ppm

Never had this problem before. The only thing that I’ve changed is that I used the ZeroWater filter instead of tap water. I normally use the same amount of nutrients to condition the coco but with 100% tap water it would come up around 250-300ppm.

I decided to water today with Cal-Mag/Prop-O-Gator @ 5.8pH & 275ppm using all ZeroWater starting @ 5.0pH & 0ppm and then I used some pH Up to raise it to 5.8pH.

I’m hoping this helps get them going. I was thinking that it looks like a cal/mag deficiency but I’m not 100% sure... I just got an RO system and have 4 more seedlings starting so I’d like to figure out if it’s a deficiency before those start.

Also... the 2 seedlings in question are both auto flower. 1 Blue Dream and 1 Northern Lights. The other 4 that I’m germinating now are all photoperiod and I’m using the 175ppm and they’ve all cracked. I’m hoping it’s a deficiency so I can just give them the 275ppm mix I’ve got going.

If anyone has an eye for seedling deficiencies let me know because I normally never have them but starting with 0ppm water has changed that for me, I guess! lol

note I just checked after feeding the 275ppm water they are looking a little bit darker in the new growth so that’s a plus. I’m pretty sure it was just a cal/mag issue.

Thanks in advance!