yes, tetras are extremely hardy fish and can and do acclimate to harder water quality. i know guys who keep neons in 8.2 ph levels. one guy actually uses water from a flooded limestone quarry in his tanks because it is pure, clean and free....lol
i have never kept glowlights, but if i recall correctly, they live about 2-5 years. i prefer the smaller tetras (neon, cardinal, von rio) and the largest ones (pirhana).![]()