replacing BioMax?

I have no idea how long the Bio Max will last but I would imagine it would last way longer than 3 months. I have used other ceramic media in filters for years without it degrading so I doubt the media will be the problem, however that media I have used was not enclosed in a bag. I would guess the bag that Hagen puts the media in would degrade quicker then the media itself. While the bag may keep the media together and make removing it easier, I would bet it will also make it more difficult to clean. I don't usually use the Bio Max but prefer to add more sponges for my biological filtration.

Thanks for the info Matt. I'd already pondered using a 2nd sponge filter in place of the carbon insert. The bag provided for the BioMax is plastic mesh (like a bag for onions) so it should last a pretty good while. I tied the bag loosely for what I hope will be easier rinsing. I'll play it by ear and if it's a pain I can chuck it and go with the 2nd sponge.

I have been using my aquaclear for more than a year. The bag is still doing fine. I don't think you would ever want to replace those ceramic rings because that's like asking for an ammonia spike.

Yeah, they're careful to tell you to replace either the sponge filter OR the BioMax, but never both at the same time. I just plan to rinse them as needed during water changes.