Hi, I am in the process of building my first pond, and I am interested in building a bog filter to do all of my filtering. As of now the pond will be in a kidney type shape, with length being about 17 feet, and the width being about 12 feet. I plan on using step down shelves to about 24 inches, and having a section about 30 inches or so- not sure if I will make this just another step.

I have been told that I can build a bog filter to do all of my filtering, and I would like to build it so that it feeds my waterfall.

My questions are how practical is this, and what size should it be? What is recommended for depth? I've been told to build it so there is at least a foot of lava rock on top of the pipe at the bottom, and finish it off with pea gravel.

Thanks