The most common species in liquid water, next to neutral
molecules, are the
and
ions. In a dynamic picture, their exact concentrations depend on the time scale at which these are probed. Here, using a spectral-weight analysis, we experimentally resolve the fingerprints of the elusive fluctuations-born short-living
,
,
, and
ions in the IR spectra of light (
), heavy (
), and semi-heavy (HDO) water. We find that short-living ions, with concentrations reaching
of the content of water molecules, coexist with long-living pH-active ions on the picosecond timescale, thus making liquid water an effective ionic liquid in femtochemistry.