Yeah I have a betta that oddly enough seems happier in a 2g unfiltered than a 20g w/ filter. I do change the water 100% every day on his tank since it's not filtered, but it's only 2g so not a big deal to me (not when I have so many other tanks I have to mess with anyway lol).
Keep in mind that if you mix distilled or lower pH water with your bettas water the pH may NOT go down in his tank since you likely have a very high kH. Higher buffering means less pH changes, which is GOOD even if the pH doesn't noticably drop.
The main thing is bringing that gH value down and also lowering your overall total disolved solids (a TDS meter would actually come in handy for you and they're fairly cheap) and contaminants. If the pH stays at 8 or 8.5 that's not a huge deal so don't worry about it. The other parameters are much more important as long as your pH is stable.
Hopefully that made sense, I'm not always too good at explaining this stuff lol.
Last edited by MyBirdIsEvil; June 26th, 2008 at 10:23 PM.