Dimidiate I can see can see where there coming from about ph and gh not matering as much, though i would only say that applies to some of the hardier and farm raised fish and as long as your ph isn't over 8.That being said you need to know what the water quality is when it comes out of the tap...
Ya betas will build bubble nests almost every where, and that are incredibly hardy fish so that will take a lot of abuse with out people noticing, he'll when I was younger and didnt know better I kept a beta in a gallon jar for two years with maybe a water change ever month or two so getting to...