Stripes are unreliable. Unless you have something in your tank dissolving into the water (rocks perhaps), you should not read that high KH
. <BTW, pure distilled water has no buffering capacity at all & might get you into pH trouble down the road ..... most people would be better using straight tap water.>
At any rate hardness of 120 (ppm
- I would think) is not that bad. My water is at 180 or so & the betta did just fine.