I am very slack on filters, if we read others here. I do what
@AbbeysDad does - wait for the flow to reduce, or, with my many box filters in killie tanks, til the media is looking bad. That takes months.
I'm 57 years into fishkeeping, and have survived to retirement. I have been trying a more organized system of water changing. I used to aim for a week to 10 days, but I didn't record keep. I couldn't have a set day, every Sunday morning type plan because of other responsibilities. I thought I was dead on with the gaps between changes.
Once I set up a small whiteboard in my fishroom and started following closely, I realized I wasn't nearly as methodical as I wanted to be. I've been holding at large water changes for every non killie tank every 7 days of fewer, and killies every 10 days for a few months, and the differences in breeding activity have been striking. I have fry from things I didn't think I could breed without all kinds of careful preparation. There's no better indicator that things are working than fish breeding, and the ones I keep tend to spawn on a regular basis in the wild.
So I go with large water changes (I have unmetered quite soft and very clean tapwater) but my filters are a bit ugly. There are plenty of micro-organisms if I go away. I raise fry in tanks with gravel and plants, and if I go for a few days, they are bigger when I return. Makes me feel useless!