Floramite is a miticide, and will certainly take care of spider mites, and I just realized that sciarid flies are fungus gnats. Suspecting they were fungus gnats given your description makes a lotta sense now. XDSpray them with "FLORAMITE" and they will be dead. Mix 4 drops per litre and soak your plants with it via spraying them. This works for 28+ days and will destroy mites.
http://www.cdms.net/ldat/ld5GE007.pdf