I would be more concerned with the 4 clowns in the same tank than if they will host it or not. Not all clowns will host a nem, some will host corals or even powerheads. lol
Also, like metioned above, the tank does seem new. Nems require an established tank, preferably over 9 months old, pristine water and super lighting......
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.