standard & accepted practices are good at standardizing things
no one will have any exceptional results
any issues that do arise will fall between standard and accepted issues on the problem
resolving any problems then involve standardized procedures to correct the issue
then there are those who do things a little (or a lot) differently.
i'm not entirely in agreement with beaslebob's promotion of things, but that's a personal issue, no basis on facts of any kind, ... regardless, beaslebob still has an amazingly simple way of doing things that goes against the standard & accepted ways of doing things, and getting plenty of success
i'm following the same route in some regards, ... and others i seem to be moving even closer too.
there is good and bad with standards
good, problems are easy to identify & easy to fix
the bad, if anything else is going on other than 'typical' then no one knows what is going on, no one knows much, nor has anyone ever bothered to consider "what if?" learning & understanding stops and so do improvements.
beaslebob is right, water changes can be detrimental.
an established tank, if left alone, can develop the exact right conditions to be near maintenance free, a hardness in the water to resist sudden changes, a stable and strong bacterial culture to keep maintaining things.
water changes reduce these buffers
now not to go gung-ho and refuse water changes, but know what your doing,
now that's what this thread has been about, to learn what is going on, what to expect, what to look for.
tests, test kits, testing, ... they'll tell you what's going on, but not what to do about it.
they'll let you know if things are higher or lower than what you want (for whatever reason, whatever you may want), ... but what to do about it, ... well you can't do anything about it, ... once the tank is set, the tank tries to keep everything at that level, it will fight you (and often win)
the only thing you can do is fight with a bigger weapon, ... and then you've gotta worry "how is this going to affect the chemistry of the tank"
test kits will only tell you what is going on, it will not tell you what to do, and what you do will in turn affect the tank in other ways very likely.
i've got a pH test kit
i've got pH 7.0 buffer
i've got an ammonia test kit (i could throw this out - if not for a remineralizing plant clippings from the tank - worried about as the plants break down a rise in ammonia, so far that's never happened)
a tank will try to stableize itself.
now if it stableizes the way you want, or the way it wants, well the tank wins, or you have to do a lot of maintenance that might cause more stress on the inhabitants in your tank than you wish, ... and once your your back to "leave the tank to maintain itself"
doing things the standard way, it's good to start, but don't stay there or when there's problems everything will fall apart and you'll be scratching your head wondering what happened., and no one will have any answers for you.