Can't keep seedlings alive

Hydroguard would remove the question. I can just say u litteraly have no roots, with a tail that long the plug should be erupting with others chasing it.

All the plants look worse. You sure you have enough bubbles?

I agree they all look worse - except for the basil and rosemary, which seem to be unaffected.

For bubbles I'm using a 20W pump: https://www.amazon.com/dp/B08DXGQN3T?psc=1&ref=ppx_yo2ov_dt_b_product_details

Tomorrow I can try swapping out the res, maybe all the PH adjustments and extra CalMag screwed it up?