Betta Fish: White wiggly worms appearing in my tank during cycling — what are these?

Hi, I'm cycling my aquarium, and I'm currently at beginning of week 2 of cycling. Here's what I've done so far:

1. Added RO water + Aquarium salt + Beneficial bacteria starter
2. Added Hang on Back filter with sponge + default floss cartridge + few ceramic rings
3. Added white sand as substrate
4. HOB runs 24×7, I've added 4-5 food pallets to help with beneficial bacteria growth. Turn on lights ~3 hours every day

And, now I'm starting to see white tiny wiggly worm like floater in my tank. I'm not sure what these are.