The discovery of superconductivity at up to 55 K in a series of iron arsenide and selenide materials has ignited huge interest. These compounds show unique features that are leading to the development of new theories of superconductivity in close proximity to magnetism. Intercalation of ammonia into FeSe turns it from a 9 K to 43 K superconductor. We have recently identified an intermediate phase in the intercalation reaction which is richer in ammonia but has a 39 K transition. In this experiment we plan to use muons to compare how the key parameters (penetration depth, superconducting volume fraction, presence of magnetism) relating to the superconducting state are affected by the intercalation of additional ammonia.