Madani Pearls About Recitation The Holy Quran (20/21)

When the recitation of the full Quran is completed, it is better to recite Surah Al-Ikhlas 3 times. This also applies when offering Tarawi Salah; however, if completion is being done in Fard Salah, do not recite Surah Al-Ikhlas more than once. 

(ibid)