OK this one is partly because I am curious and partly for fun. Mostly it is to get an idea of how others maintain their tanks.
I do a 20%-30% water change every week on my 32g freshwater tank, depending on the Nitrates (NO3) reading. I find that this works well for me. However, I often read posts where folks do 40% or even 50% and the frequency also varies between weekly to bi-weekly to monthly. I am not talking about "problem maintenance" but regular maintenance.
So... how big a tank do you have and how much water do you change at which frequency? And why?
Guess I screwed up the title there eh?