ANSWER: 

If you don’t recite anything after al Fatiha, your prayer is still valid. 

If the ayah holds a complete meaning, then only one ayah can also be recited after Fateha, for example Ayat Al Kursi. 

What does Saheeh Ahadith Say about Recitation of Number of Ayat After Surah Alfatiha. I mean to say that is it compulsory to recite atleast 3 ayats after Surah fatiha or 1 ayat equal to surah Kousar? Can we recite only 1 or 2 ayats after surah fatiha?