Hello, I plan on modifying my 29G (30x12x18) and making three shrimp's tanks. I think I would put 2 pieces of plexi or glass (not sure yet) in place with silicone. I want something that would not allow shrimps to switch zone. But, I am wondering if (and how) I should allow water to flow between the three spaces? And also, how to plan my filtration. Any ideas? Suggestions?