These are all shot with Canon 100mm lens. Usually low F numbers and fast shutter speed for fish since they are moving targets. Macro shots are the opposite since you want to gain some depth of field in you target.
I've no magic formula for my reef photograps and I use various lenses, lights and methods to get acceptable results.
Sunlight in my tank is rare, but here it's used as main light with some actinics backlighting.