Clearing solution residue?

What is this gel substance? Noticed this after starting a flush.

Looks like soil crystals ( Water retaining Gel ) , this is commonly added to houseplant soil and Miracle Grow has a version of soil with that junk in it too and I am thinking that is what this photo shows !
Miracle Grow Moisture Control Potting Soil

I'm growing in coco (???)

Are they squishy like gel? Or is it crystallization of mineral salts and hard?

Soft like a gel