Hmm, I'm looking and wonder what the difference is in materials. I'm thinking about ordering the #3 size that are 8 1/4" long as I'm not crazy about the 14" length of the current ones and would prefer an 8" one I could change every day. I think 10 of those would be sufficient for me. I don't know what mesh to go with: nylon, polyester, or polypropylene? And I can't decide between 200 and 100 micron bags, $0.45 difference. I have the 100 now, and I'm not sure how quickly they'll stop up if I get a bag sock that's shorter.