B, I just add Kalkwasser for topoff. No buffer or anything else added, but a 5% or so WC weekly. I add baby brine, DTs phytoplankton, and the 2 smallest sizes of Golden Pearls for food, and the natural plankton in the seawater. The cool thing is that the acro is almost on the substrate--this LOA light is really suitable for SPS, even 8 inches or so away from the bulb.