  In this work we classify the subalgebras satisfied by non-geometric Q-fluxes
in type IIB orientifolds on T^6/(Z_2 x Z_2) with three moduli (S,T,U). We find
that there are five subalgebras compatible with the symmetries, each one
leading to a characteristic flux-induced superpotential. Working in the
4-dimensional effective supergravity we obtain families of supersymmetric AdS_4
vacua with all moduli stabilized at small string coupling g_s. Our results are
mostly analytic thanks to a judicious parametrization of the non-geometric, RR
and NSNS fluxes. We are also able to leave the flux-induced C_4 and C_8 RR
tadpoles as free variables, thereby enabling us to study which values are
allowed for each Q-subalgebra. Another novel outcome is the appearance of
multiple vacua for special sets of fluxes. However, they generically have g_s >
1 unless the net number of O3/D3 or O7/D7 sources needed to cancel the tadpoles
is large. We also discuss briefly the issues of axionic shift symmetries and
cancellation of Freed-Witten anomalies.
