Too fast through the Bible.

Is it possible to read through the Bible too fast? Silly question I know. My high schooler is working through a boxed curriculum right now that incorporates History (ancient)  Bible and Literature. It isnt working well for us, but I paid good money for it so I need to make it work. Basically he is using a textbook with supplements for history, reading through the entire OT in 180 days and reading ancient literature. This is not a particularly academic child, not a strong reader. I am thinking maybe 5-7 chapters of OT is not sticking with him. I am concerned he is getting it over with, rather than savoring the Word of God. I have already chucked the textbook and replaced it with Unwrapping the Pharoahs and Famous Men of Greece, I eliminated some literature and will replace Homer with the Sutcliff versions, though I will have him read excerpts of the Iliad and Odyssey  to get the feel for them. I feel like I am tweaking so much I might as well give up the curriculum entirely! I guess my question is continue to read the entire OT just for the sake of getting through it all, or slow down and take more in.