Generally these types of bowls goes into a stage where you just top off the water and chance it every 3-6 months. But you have to condition it to that point.
Like tattooedfool83, add some residents (snail or shrimps, i won't suggest fish unless its one betta), water change every other day for about 2 weeks, then every 3 days for 2-4 weeks, then once a week for 3-6 weeks, then once every other week, so on and so forth.
This is without testing the water. You can do it with much better accuracy if you test the water before every scheduled water change to see if you can skip it or not.
This only works if you have appropriate amount of plants. Meaning you have to have enough plants that can consume all the waste produce by your residents.
Of course if you are looking to have a sparsely planted bowl, then you should stick to a more rigorous water change schedule.