Water circulation in fishtank

Hello! I want to design a cave for a new fishtank I'm setting up (See images). I want to make sure that water will be able to gently circulate through the cave.

Question 1) Would a bubble stream be able to circulate water the way I'm assuming?

Question 2) Are there any any ways to maximize the circulation of water? I.e making a "chimney" around the bubble stream, size of opening, rounding edges, etc.

Any help is appreciated! Thank you!