2 questions you asked.
First was turnover. 18.5 is not too high. Actually 30-50 is recommended for reef tanks. A circ pump to blow water around will be beneficial.
Second was lights. Anemones need high lighting. You have a few options. A fixture with a MH
(metal halide) bulb and 4 T5HO actinic bulbs is an option but it can heat up your tank. Or a 6 or 8 bulb T5HO with a combo of actinic and Cool K
rated bulbs will work but the bulbs will need to be replaced annually at a significant cost. The latest is led
lights that give what you need for light and don't need to be replaced annually but might cost a bit more upfront.
Taotronics seem to be very popular for many members and perhaps someone will pipe in with a specific fixture recommendation.