Hiwi
Hiwi - CO2 Technology Made in Germany!
Hiwi is a renowned German manufacturer of CO2 pressure regulators, offering high quality at a fair price. The range includes pressure regulators in various designs, optionally with built-in check valves and night shut-off. Particularly interesting are the dual-stage pressure regulators, which keep the working pressure constant even as the cylinder pressure drops. Standard pressure regulators compensate for falling cylinder pressure with a higher working pressure, which results in more CO2 being released into the aquarium. Under certain circumstances, this can endanger your livestock. Dual-stage pressure regulators are a safe solution for an aquascape or aquarium with lots of aquatic plants and livestock, even when the owner is away for longer periods, for example on vacation.