Sump design, why so many chambers?

[kien]

I have a two chamber sump with a bubble trap separating the two chambers.

1. The bubble trap is a life saver with my skimmer because my skimmer likes to occasional spit out bubbles. The B-Trap eliminates said bubbles.

2. I like to float stuff in my sump and it's nice to do that in the non-return chamber so that something doesn't accidentally plug up the return.

3. I find that I get a lot of settling in my non-return chamber vs my return chamber. My return chamber is fairly small so I suspect everything in that chamber gets sucked up and spat back into the tank. In the non-return chamber there's time for stuff to settle at the bottom of the chamber which I can then suck out during water changes.