I’m a beginner and only know what half of that means

What exactly is 0.1 um?

There's a type of water called phosphate buffered saline. It's exactly its name: saline buffered with phosphate, to resist ph change. Some people swear by it to avoid benzyl alcohol in bacteriostatic water that can be bad for some peptides. I get pbs free from work and just to be safe I will fill a 10ml syringe and push the PBS through a 0.1um disc filter then reconstitute my peptide. I used this water to spray ghkcu and kpv nasally and it worked well

I push the water through the filter into a new sterile vial. I'll filter 10ml at a time and keep it in my fridge and just try to be as clean as possible when pulling water out to reconstitute. Always wipe with alcohol and let it dry. The drying is what kills the germs