Assuming your parameters are within reason these corals are actually pretty undemanding when it comes down to lighting and flow. They tend to do better with quite a bit of light and a lot of chaotic flow IME. (and a secure base) As far as proximity goes most other softies are ok up close, but ultimately your just going to have to see what works and go from there. (trial & error) The link below goes into some detail about keeping Toadstools, but it's pretty much the same thing with the Sinularia corals as well. GL.