The filter cartridge works like a waste bin, trapping dirt, once full it should be thrown away and replaced with a new one. To keep your biOrb or biUbe at its best, this should be done every 1-2 months. A partial water change of 30% should be carried out at the same time... 
Features:
- Replacement filter cartridge
- Algae cleaning cloth
- Sachet of water preparation chemicals
- Simple to install
- Full instructions included
