AquaFX The AquaFX Dolphin RO System - Manual (Page 9)

For R.O. (Dolphin) users, they may wish to purchase DI to remove the
ammonia..
RO/DI (DOLPHIN, Mako, and Great White) users will have the ammonia
removed by the DI. This will tax the DI, Chloramines appears in several
forms, so the decreased life would depend on the state of Chloramines.
(mono, di or tri)