I just buy a roll of filter floss every few months and chop it up. Change it 1-2 times a week and toss the old one out while rescuing whatever brittle stars or limpets that found themselves down the chute.

yes 2 socks, 100 micron, changed every 3 days, i tried without but too much floating debris, micro bubbles, and junk in the sump.

90 gal mixed reef, heavily stocked and well fed

I hate my filter socks. But at the same time, i love them. I ran without them for a long time, i can't believe how much cleaner my tank looks in general with them on now. It's worth the maitnence every other day to keep them clean. I hang 2 off my return pipe in my sump and once i have 3 dirty socks i do a laundry load. Beats cleaning hair algae out of a reef :(.