You are right,
the most beautiful tanks out there are tanks with tap water.
One of Nicolay's issue (mine too), is to limit water changes to a minimum.
Later I started dosing my tanks heavier and some did great and some had problems. The common things for all of them was that I had to keep up with the fertilization and water changes or else.
We all know, that dosing heavily with unconditional weekly water changes work great.
Now, changing 50% water in a 15 gallon tank is quite fine, but maintaining several larger tanks like 130 gallon week by week? There is no more time left to enjoy the look of the tank.
This is why we are looking for an alternative.
I fill up a tank with RO water run once over a dolomite bank, the water is 40uS. If I dose once NO3 10 ppm, PO4 1 ppm and K 6.6 ppm I get 70 uS. A week later, there is still 70 uS and the nutrient ratio is off. Only option left is water change again.
But, if I dose daily NO3 0.1 ppm, PO4 0.01 ppm and K 0.066 ppm, a week later, there is 40 uS. No need to do the water change. The added nutrients are consumed without leaving anything behind. No contamination, no need for a water change.