Am I overstocked?

[naesco]

Originally Posted by bleevin

The tank owner previous had the tank setup for about a year and I've been running it for about 3months. The current size of the tangs & trigger is about 4inches - 5inches. The tank came with a kz Revolution S skimmer. The tank is a 4 footer.

It sounds like I should consider moving the sail fin out, which could make room for more fish?

Absolutely. A four footer is too small for any tang species with the exception of the kole tang.
The reason is tangs are swimmers and need the swimming space longer tanks provide.
Smaller tanks don't allow the the change to motor up and swim.

If you like tangs consider moving up to a 6 footer.