It's a honeycomb perc on the bottom and then a shower head above that. Any advice is greatly appreciated!
I'd do half on each. I haven't had a double perc like that for a few years. If I remember correctly you fill from top. That or it's from the bottom tilted back. Then blow air in to get desired level. My First Grow Ever! Journal
I would say an inch over the slits on both. Different people like different amount of water levels though. I also think it depends on how you smoke it, if I'm pulling the smoke slower (before I pull the slide) then I prefer higher water levels. If I'm pulling it faster I want lower water levels.
Have a go and find out =) Water levels in bongs are all personal preference; some people might only fill the top chamber and use the bottom as a dry ash catcher. The more water you have doesn't necessarily mean it's going to filter better, it just means its going to pull faster or slower and harsher or smoother respectively. It's strange to say now if you've never used one but after a while you'll learn which chambers water level is adding more resistance and you'll learn to get your sweet spot in both. You don't have to be smoking anything to test all of the above either, just have the bowl on but empty.