CUSTOMER AND PROFESSIONALS CHOICE - Our 200 micron size filter socks are BEST SELLERS - the TOP CHOICE for my clients as well as my aquarium service technicians and both chose 200 micron socks because they do not clog as quickly as smaller microns do, yet they HELP ENSURE CRYSTAL CLEAR WATER.  HIGH QUALITY AND REUSABLE - Solid construction and heavy duty stitching make these socks STRONG AND DURABLE so they CAN BE CLEANED AND REUSED numerous times. NOW with STRONGER THICKER tie string.  CUSTOM MADE with DRAWSTRING - Our filter socks are constructed only when our factory receives our exact specifications; YEARS OF TESTING produced the perfect blueprint. Other socks may look like ours but if you want the best you have found them. IMPROVE WATER QUALITY - Our filter socks have interlocking micro-denier felt fibers that are perfect for trapping uneaten food, waste excreted by livestock, decaying plants, detritus, dust, and other floating particulates. Changing filter socks regularly will INCREASE WATER QUALITY by removing solid organic compounds before they continue to break down and add additional nutrients (which can increase algae growth) to your aquarium water. TIPS AND RISK-FREE GUARANTEE! You will receive OUR PROFESSIONAL CLEANING INSTRUCTIONS INCLUDED with your filter socks. In addition, we are committed to our 100% CUSTOMER SATISFACTION so if you find that you are not 5-Star happy with us or our products, please contact us and we will do whatever it takes to make sure you are 100% satisfied. Our Filter Socks Help Keep Your Aquarium Clean and Healthier  The interlocking micro-denier felt fibers are perfect for trapping uneaten food, waste excreted by livestock, decaying plants, detritus, dust, and other floating particulates. Changing filter socks regularly increases water quality by removing collected solid organic compounds before they continue to break down and add additional nutrients (which can increase algae growth) to your aquarium water.    Directions Rinse new filter socks with clean fresh water and wring them out before using them in your filter. How to Clean Our Filter Socks You can find the exact steps we recommend to clean your filter sock by clicking our resource tab and find the article titled "How to Clean Filter Socks and Filter Bags" or you can click here. Our Experience I owned an aquarium store (and a separate aquarium maintenance company) for over 25 years during which I spent a lot of time and resources searching out and testing countless filter socks to find the best for my clients. Fortunately, one stood above the rest giving consistent and repeatable filtration performance in all types of aquariums. These long-lasting heavy-duty filter socks are the best the industry has to offer!