How often to clean cannister filter?
I've had my Eheim 2215 up and running for just over a year now and haven't cleaned it out once. I'm thinking maybe it's getting to be time even though I don't really have any indicators that it's getting dirty. If the flow is reduced at all I wouldn't really notice, it's on an ADA 60p (18gallon) so it's probably more than enough flow for the tank.
What do you think, any advice on how frequently I should be cleaning the media? I'm assuming I'd just do a partial water change and save the water in a bucket to rinse the media bags out in, then refill w/ tank water and get it started up again? Sorry if this is a dumb question, this is my first cannister filter and I've never had to clean it yet.