CUSTOM MADE: 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.    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. THESE DO NOT FIT RED SEA FILTERS   REMOVES FINE PARTICLES- Our 200 micron filter socks remove much larger particles from water than 100 micron socks producing polished, CRYSTAL CLEAR AQUARIUM WATER. In order to catch such fine debris they will not clog up faster than 100 micron filter socks.    SAFE FOR YOUR AQUATIC FRIENDS - Strict quality control ensures our filter socks remain aquarium-safe all the way from our USA manufacturer to you. You can now BUY WITH CONFIDENCE knowing that your filter socks will not come into contact with any harmful contaminants and will always arrive at your door safe for your aquatic friends.   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 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 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!   FILTER SOCKS FAQQ: Is the 100 micron or 200 micron better for my aquarium?A: The lower the micron rating, the more floating debris it removes hence the filter socks clog up faster. Many hobbyists have both the 100 and 200 micron filter socks which allow them to swap out their 200-micron socks from time to time.Q: How often should I change the filter socks?A: It depends on the tank load, but generally you want to change your filter socks once a week or every two weeks. The more often you change your filter socks, the better your water quality; it removes organic solids before they have a chance to further break down.Q: Is it better to use a longer sock with more socks hanging in the filtered water than a shorter one?A: Ideally the filter sock should be hanging in the water without touching or laying on the bottom of the sump. If a shorter sock is above the water line there may be more noise as water drains from the sock side and splashes into the water In your sump.Q: Is there a glaze finish on these filter socks? the glaze makes them less flexible and stiffer. or are they untreated?A: Our socks are untreated. The felt is soft, flexible, and perfect for trapping floating debris from the water.Q: Has anyone verified if Aquatic Experts filter socks will work with the reefer?A: We have personally tested Our filter socks in the reefer sliding shelf sock holder. Our filter sock material is thick and our plastic ring is slightly too large to drop through the hole in the shelf.Q: What makes Aquatic Experts felt filter socks better than any other brand?A: Owning an aquarium store and service company for 25 years meant that we had to test countless filter socks to find the best ones. One stood above the rest giving consistent and repeatable filtration performance in freshwater, saltwater, and reef tanks.