I had two 750's koralias in my 29g so it can be done.
I usually put one on each side glass and aim for the front middle of the tank with a slight upwards angle. Both flows should hit each other and create a really chaotic flow that will leave no dead spots on your sand or rock.
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.