[AquaticLife] Filter Question
Never… well, almost never… unless you listen to the filter companies who say every 2-4 weeks.. but then they want to sell you lots of filter cartridges. 
See my long article about “Filter Maintenance And Cleaning” for more details of how I and many others “clean” our filter cartridges and other filter media without ever throwing them away. Filter cartridges, sponges, poly pads, etc., should last for years and years. The only time you need to trash it is if starts to actually deteriorate. I haven’t trashed a filter cartridge or any other filter media that I use (see my article) in over 3-4 years… and counting… since I set up my newest tank(s).
Even after several years, if the actual filter floss or sponge starts to deteriorate, you can usually buy just the replacement media and still use the cartridge frame. I will just rip/scrape the old pad off and wrap the new blue/white filter pad around the cartridge and slide it in place but I guess if I wanted to be fancy, I could cut the new piece of filter pad to size and glue it in place with some aquarium silicone or aquarium safe epoxy.
Lenny Vasbinder Fish Blog - http://GoldLenny.blogspot.com (Links to any articles referenced in above reply are listed on the right side, alphabetically under Labels and also under Archives by Year, Month)
Category: Philippines Internet Koi Society
