Welcome to the forum....
One of the best ways to avoid 100% water changes is to establish the nitrogen cycle and another is using live plants.
Regardless of tank size or filters-water changes are still needed in a closed system.
IMO/E-filters are optional for this species, however, to establish the nitrogen cycle you will need some type of aeration by either a filter, airstone or live plants to provide the needed oxygen for the beneficial bacteria.
Here is a sticky that might help give you more info.
http://www.bettafish.com/showthread.php?t=107771