Periodic large water change?

[Cell]

For those that do regular water changes, do you always change the same volume of water every water change all year long or once in awhile do you do a much larger water change?

I typically change about 15% every 2 weeks but a couple times per year I'll do 30% to clean the tank up and kind of replenish everything.

 

[4tanks]

Regular 10 percent a week and if I see nitrates creep up I may do a larger one but if there is no problem then no point trying to fix it

 

[Waters]

I do AWCs now (which are always the same) but the only time I ever changed more than my normal amount manually, it was only because I wasn't finished siphoning the substrate and needed another couple of gallons of water to finish lol.