Al Humdulilah I have learnt to read the Quran by the way of Hafs an asim min tareeq shatibiyah and I would love to learn the other ways of reading the Quran as well.

Question
Assalam O Alaikum

Al Humdulilah I have learnt  to read the Quran by the way of Hafs an asim min tareeq shatibiyah and I would love to learn the other ways of reading the Quran as well. How long does it take to learn each way? Is it necessary for one to have the Quran fully memorized to learn the ways of the other readers? It would really be nice if you can tell us briefly how the other ways of the Quran differ from tareeq ash shatibiyah.

May Allah reward you for all your efforts by helping the Muslims all over the world ameen.
Wasalaam

Answer
Wa alaikum assalaam wa rahmatullahi wa barakatuh,
May Allah give you much khair in what you have learned. 
We would highly recommend that you spend your time memorizing the Qur'an in one way before going on to learn another way.  Memorization of the whole Qur'an is a lofty goal full of great rewards and benefits from Allah, and this should take priority over learning other ways of recitation. 
There are 52 ways of Hafs 'an 'Aasim from the way of At-Tayyibah and the differences between these ways (tareeq Ash-Shaatibiyyah is one of the 52 ways)  is not great.
 There are 10 different qiraa'aat each with two riwaayah, or narrations.  Some of the qira'aat and riwaayah are very different from Hafs, others not so different.  It is really quite difficult to summarize the differences, as almost all require a great deal of explanation. 
The length of time it takes to learn each of the other qira'aat depends on the students time, desire, and drive as well as the depth the teacher goes in to when explaining.  After learning the theory, the student needs to practice reading that way, then go on and read the whole Qur'an to a qualified teacher.  To get an ijaazah, this recitation needs to be done by memory. 

May Allah make it easy for you to memorize the complete Qur'an and then continue and learn the different qira'aat.
Wa assalaam alaikum wa rahmatullah