Your using soil/dirt in the bog area?
Can you just use various sized gravels? I would think it would be cleaner in the pool as some particles are bound to get released from the bog and settle in the pool. I say this since I removed some runners off my Bull Rush, that was planted in straight gravel, and it had an obscene amount of dirt and debris trapped in the roots. I thought the roots were going to be clean, but I was wrong. Over the years they have trapped countless leaves and stuff that trashed my water clarity for 3 days.
Just food for thought...