I've been using the 5 micron BRS carbon filters and end up having to replace them just about every 6 weeks. I'm only using for top off and water changes. I have a 5 and 1 micron sediment filter before the carbon and they still tend to clog way too fast. Can someone tell me who has good carbon filters? It certainly would be beneficial to many if you know where to get good quality at a good price.