I'm not sure but I saw boxes and boxes of them and they definitely had plenty. I'm stopping by Reefwise in an hour and I think they had some too. I'll text you with what I find.
No they will not. I've never seen anything that fine anywhere. Usually Filter socks are 100 or 200 micron. I use 53 micron sieves for copepod eggs. 4, 5 or 10 will filter out everything and have very very very low flow.
Josh, I understand 4 to 10 Micron will filter out everything and slow. I need those for binding phosphate...I hope I can find in local, otherwise will order online.