We report the growth of doped potassium lithium tantalate niobate (KLTN) crystals and characterization of their physical properties. The top seeded solution growth method is described. The specifics of a particular KLTN:Cu growth are presented, and the resultant crystal is described. The dielectric properties are compared to those of KTN; the addition of lithium is demonstrated to change the character of the phase transitions as well as increase the transition temperature. Phase diagrams for the KLTN system are illustrated as a function of lithium and niobium concentration.