Doing super frequent water changes.. what can go wrong?

[sphelps]

Another interesting theory to consider is: No matter how much water you change it's not enough to maintain ultra low nutrients. Something else, like a skimmer for example, is always needed.

Even if a tank starts at 0ppm nutrients, and only adds 0.5ppm a week and you change 25% of water weekly you'll still build up to a stable level of 2ppm. This may not seem like a lot but keep in mind it's just an example to show the theory. You will never maintain 0 nutrients with water changes alone.