Can You Mix & Match First and Second Stage Regulators?

When you dive, always check that your equipment is in top working condition as you are effectively putting yourself on life support. You get the air from your tank through the first-stage regulator, which passes it on to the second-stage regulator; this is the one you breathe from. It is possible to mix first-stage and second-stage regulators from the same manufacturer, but otherwise this should not be attempted when purchasing new regulators.

  1. Function

    • The function of the first-stage regulator is to reduce the pressure of the high-pressure air from the tank to intermediate pressure and then pass it on to the second-stage regulator, where it is reduced to breathing pressure for the diver. The air passes from one regulator to the other when triggered by the diaphragm in the second stage, opening the valve when the diver inhales.

    Mixing

    • It is possible in most cases to mix regulators made by the same manufacturer as they have the same general makeup. You can mix and match across some scuba brands, but some regulator brands will not work with others because of different pressure settings in the system or different attachments.

    Octopus

    • You can use a second-stage regulator as an octopus (alternate air source) with no problem; however, it is not advisable to use an octopus as a second-stage regulator, as in many cases the octopus is of lesser quality, which is why octopuses are normally cheaper than regular first-stage regulators.

    Servicing Considerations

    • As most first- and second-stage regulators are sold as packages by manufacturers, they will have the same service kits when they need maintenance. Having first- and second-stages from different manufacturers will increase the cost, and in many cases the repairs will have to be carried out by different technicians as manufacturer warranties require that only someone certified to fix their particular brand may work on the regulator.