Originally Posted by
smokingreefer
http:///forum/post/2706800
My current parameters are:
ph - 8.2
dKH - 11
Ca - 440
trates, trites, ammonia - all 0
It has been 3 weeks since my last water change, but my parameters are still perfect. So, do I really need to do one?
3 weeks is not long to go without a water change. There may be something to be said for changing small amounts of water more frequently (weekly, etc) - but you're definetely not long overdue. I don't advocate it, but I've seen a few lucky aquarists go for months and years without ever changing water.
That said, you should know that the parameters you've listed are only a few things we test for amongst many other trace elements, etc that we don't. Simply because those numbers are satisfactory doesn't mean that something else doesn't need to be replenished or whatnot.