Currently running on my aquarium. This is fully running with live bacteria. If you want to start your tank with a fully cycled filter here you go. Will need reconnecting at your end within 2 hours max to keep all the healthy bacteria alive. Or I can clean the filter out and you can start the cycle again. Same price either way. These are best part of £400 new. Upgrading to sump filtration reason for sale. Collect m31 4fg.