Hi bro, open brain, or trachyphyllia, is relatively easy to keep and not very light demanding. They can be put on the sand bed or even partially shaded areas with low to moderate flow. The one time I had an open brain die, it was exposed to direct blasting from the wavemaker on top of my cleaner shrimps digging it open for digested food
In addition to good water parameters, feed it fleshy food like bits of market prawn or mysis once a week (usually rows of feeding tentacles will extend near night time), and it will be enough to keep it happy.