The invention relates to a device (1) for dissolving a gas (G) in water (W), comprising: a housing (100), that is configured to be submerged into the water (W), wherein the housing (100) comprises at least one water inlet (101), a gas inlet (102) and at least one water outlet (103) for discharging gas enriched water out of the housing (100), a pump (5) that is in fluid communication with the at least one water inlet (10) for sucking water (W) from a surrounding of the housing (100), wherein the pump is configured to generate a main water stream (S'), and a means for injecting said gas (G) supplied via said gas inlet (102) into said main water stream (S'). According to the invention, the device (1) comprises a probe (6) configured to measure a concentration of said gas dissolved in water, wherein said probe (6) is arranged in the housing (100) of the device (1).
