Unusual, looks like rice or insect eggs. Is it possible that something external is dropping in the tank? I don't think I know of anything marine and living that collects in the meniscus? I'm tagging.
Do you have access to a dissecting microscope?
I never knew about stores misting LR before but that would explain how a fly could lay eggs on LR. I always assumed they were under water at stores. That is what I get for assuming.
:smck: