you don't need to separate the skimmer and return pump with baffles, but it may allow you a extra bubble barrier from the skimmer. not necessary, but couldn't hurt. IMO, aquaclear filters aren't necessary. you can run carbon filtration in it, but it is not necessary and it pull good nutrients out of the water as well as waste, which with a good skimmer, you won't have much, if any waste to be pulled out by a aquaclear filter. if you want to use it you can, some people do, i run nothing but a skimmer, and i have had great success with it.