X12 Dwarf Freshwater PufferAquarium Setup In captivity, they are not too picky about water parameters. As long as extremes are avoided, your fish should do just fine. Spawns have been reported by many hobbyists in both hard and soft water with a recorded pH both slightly above and slightly below neutral. I have kept and bred them in water with a neutral to slightly basic pH, a total hardness around 125 ppm (with about half of that coming from carbonates), and a temperature in