Alas! The last chapter in this already too long story. It is actually ya'll's fault you know. If you ask an old man about his grand kids, his dog, his old truck, or his hobby, be prepared to hear more than you wanted to know!
In the photos of the re-construction you saw the old pool skimmer box, and the pool return outlets. They were a mistake. Once everything was said and done and the new water was pumped in via the truck, I learned in a day or two I had a slow leak. I ended up tracing it to the skimmer box and decided to completely abandon any pool related equipment. I made a plate to bolt onto the skimmer box, cut an over-sized piece of EPDM, and used some of that evil black goop in a tube to seal the skimmer closed. After putting some tape on the return plugs, they got sealed too. Since then and with no piercings of the liner anywhere (not even a BD) the water level has remained constant save for the natural evaporation.
So, having thought about the bog last summer into fall, I decided to build it parallel to the "dock" above ground. This would allow gravity flow back to the pond, a minimum of piping to the supply side, and create a sort of subtle boundary to that side of the pond.
The downside was all of the established plants alongside the "dock" would have to be moved, and it was getting chilly so I had to get a move on. First thing was to move the plants. After that it was flip a coin for how big this bog would be. Proportion-wise, 20'X4'X 2' looked pretty good, so.... 50' of ground contact PT 4 X 4's for a footer, 6 - PT 2"X 8" X 16' for the sides and ends, 50' of PT 2"X 6" for the cap, 3 sticks (8' ea.) of 5/8" rebar, and 4- 8' PT 2X4's.
The first critical aspect of this project was making sure the 4X's were level. I had to build up a little on one end and scalp a little on the other end. After laying out the 4X's, and cutting and placing the ends, I positioned all the pieces and double checked the levelness. Using an adjustable auger bit set to just slightly over 5/8" bored holes through the 4X's then drove pieces of rebar through the holes to anchor the "footers". Next was laying the first "course" of 2" X 8" on edge. These were placed such that the inside was flush with the inside of the 4X. This did two things...provided a smooth interior for the 2X4 supports, and gave a "finished edge" outside of the box on the bottom.
After the first "course" was temporarily set up, four holes were dug 2' deep down each side for the 2X4 support pieces. One in each corner, one in the middle of the 16' section on the bottom which coincides with the joint on the upper course. (16' + 4' to equal the 20' run two times on each side, staggering the joints.)
I then laid in an old worn out plastic tarp, and shoveled - wheel barrowed in two yards of granite dust (sand) into the corners and bottom outside edges to provide a bed for the liner. Laid in the liner and tack-nailed the top edges in several places then filled it with pond water. The nailing was done to determine if there were any stress wrinkles in the liner. None appeared, so I thought I'd play a little.
I had calculated the water volume in the bog and ordered 2 1/2 yards of pea gravel to fill it up. While that was coming the supply line and return line was put in. By this time the weather was getting pretty chilly, and it was time to quit for the year. I cut the cap pieces, fastened them on with a couple of screws, and created a "green house" cover for the entire thing for an experiment which didn't work out because of the severe winter we had, but at least the bog was ready to test in the spring.
!
After a too long winter I was getting anxious to try this bog out. I ran some water through the system and got the "dust" washed off the pea gravel, but had used the hose and diverted that part to the yard. Once the water ran fairly clean the return was set back to the pond. One thing I discovered here was, the hose return would be a bad idea in our circumstance. One twig, and a couple of leaves would allow the bog to over flow and if not tended to quickly cause a problem. My solution was to build a box that protruded into the end of the bog to create a catch basin for anything that might otherwise clog the return. From this box, it's a free fall into a sluice box then back to the pond. With this arrangement it's almost impossible for the bog to back up.
As you can see in these last few photos, the return isn't quite finished, I have some finessing and cleaning up to do, but that's about it.
That's my story, and I'm sticking to it! Thanks for your patience!