I first primed the drywall ceiling with 2 coats of latex ceiling white. Then the knockdown application was completed and now dry.I now want to paint the ceiling white.
My question is, can I use a good quality latex paint or do I have to use a oil base. Thanking you in advance.
For future reference, you should have used a primer, not paint under the texture but that is water under the bridge now. Primer and paint are two different things, with different properties, and for different purposes.
No reason at all you need oil based over the knockdown if it is just drywall compound? You should prime before you paint though to seal the knockdown and give a nice surface for the paint to adhere. I would just use a quality latex primer, than two coats of finish.