<_< Got a new book on keeping goldfish and the author said that if your filter is good enough and you dont overfeed then you should not need to change the water in your tank for five years, and only top it up with water for loss through condensation. What do you guys think? Has anyone gone that long without changing the water and is it possible? I got as far as two weeks and done a 20% change as i felt uneasy about it but i am going to try a bit longer with careful monitoring of water quality and see how long i can do it for.

Not me, I'm not taking a chance with my tank or fish.
Doesn't he realize it is much easier to head off a problem than to fix one??? The water chemistry can change rapidly and then what? I'd much rather keep a problem from developing than to battle sick fish.


On a side note, when I was young and didn't know how important water changes were, I went 1 year without changing the water. I did just what he did. The tank was always gross and shortly after that my fish kept getting sick and no matter what I did to save them they died.

No not me, I'm not taking that road again.
Best luck to you though.

For me the rule is opposite:

If you have enough room and enough water changes you should never really need medicine.