really no such thing as too much flow, for microcrustaceans... or really most any other creatures practically kept.
The calmest reef you will ever see is still staggeringly more dynamic than the most turbulent aquarium. The real issue with "too much flow" is the application (direction... as in too linear/laminar) and not the (high) volume. It is the very focussed linear flow pattern such as with powerheads and pump nozzles that is so very awful and unnatural for many reef creatures if unmodified in aquaria.
So by providing the wide rolling (indeed laminar but diffused) flow as with a tumbing chaeto ball... or the fab turbulence of a multi-tee manifold like some do on displays, we can sufficiently diffuse water flow while still enjoying high volume.
As far as the 12/12 photoperiod... it is a must! One of the biggest mistruths in aquarium algae culture is that all or many species can endure an uninterrupted 24hr photoperiod. Not true! Not even close. Most will suffer and dwindle in time without adequate time (night) for respiration. Among commonly available plant and algae species... only some Caulerpa will live well in stasis with constant illumination.
Really... the majority of marine plants and algae will thrive, if not need(!), a proper and natural day/night photoperiod
12/12 is fine with most lamps. Focus more on finding warm coilored lights of high PAR value.