Buying a new bowl (newbie)

I just bought this bong and the bowl's hole is too big so a lot of green falls through. I'm looking to get a new bowl but I don't know the size that would fit with the downstem on it. How do I find that out? I'm new to having my own bong. I attached pictures.

just put a screen will cost you like 25 cent

^What they said +1

just throw the bong away its a leady anyway