Originally Posted by fatrip
but if you have good gas exchange and are adding trace elements, like calcium, and you are taking all of the decomposed matter in the water out through refug, skimmers, wet dry fillters, i dont see the need to change the water, unless something drastic happens to it, like a dead fish that you didnt catch in time or one of your children putting somthing into the tank.
Who adds every trace element? Trace elements include things like copper, manganese, etc.
No one doses (and tests for the right concentration of every trace element). Not to mention how costly that would be versus just doing a water change.