How often do you do water changes?

[marie]

I was doing bi weekly water changes but everything has been doing so awesomely well I haven't dared do anything for awhile so I checked off the "strange schedule that makes sense to me" option

[Chowder]

I do 15g a week on my 85 gallon total system and 15 gallon week on my 116 gallon total system at work.

[Ruth]

I checked off the strange schedule. I try to change about 20-25g once a week on my 110g cube (probably 150g total volume). I usually do my 2 nano's at the same time with about a 50% water change. On my 230g and 190g I am probably more at the 2-3 week interval.