Bog Filter - Day 3

At the bottom of the filter goes the pipe distribution network. I opted for 1" PVC and I cut slots every 3/4" or so down the length of the horizontal runs. The vertical runs at the ends are capped and available for cleanouts.

The distribution system goes into the bottom of the pond. Pat had fun experimenting with new photo editing software. Thanks Pat!

The pond gets filled with 3/8" pea gravel. This provides the surface area for a bacterial film to develop, allowing biological growth to reduce the nitrogen. Further nutrient reduction takes place when plants are placed into the gravel. The water level in the bog is just even with the top of the gravel.

This is what a half-ton of pea gravel looks like. It is pretty dusty when delivered so it must be rinsed before placing into the filter, otherwise you just introduce all that rock dust into the pond system.

So I figure that I shoveled a ton of gravel that morning - first into a bucket to swish around with water, then into the filter.

Now the bog filter is full to a 12" depth with gravel. We put a piece of plexiglas onto the low point to create a small sheet-flow waterflow into the pond. Now we'll see if it works...