Duck bog redo

[allif]

We built a bog for our duck pond last year, worked great until it didn't. Not sure what happened but my theory is that our plants didn't establish themselves well enough and when our chickens finished them off we didn't have sufficient filtration. We ended up with some leaks we never found and upon dismantling the entire bog an enormous amount of solids. We're rebuilding the bog now. Over half of it is now inaccessible to the chickens, so hopefully we'll get enough biomass growing to keep the water (and the bog) relatively clean. We're thinking of only perforating the pvc at the far end of the bog, to force more filtration.
So water would come out in the chicken free side of the bog and work it's way through the gravel towards the spillway.
Here are our questions.....
- Our clean-out pipe never worked. Not sure how to fix that. I don't understand the physics enough but seems to me those can't work in general with a perforated pipe? What am I not getting? I don't see the value if you can't use it to clean out the gunk periodically.
- Should we raise the pvc pipes off the floor of the bog by a few inches to allow for sedimentation?
- Should we add a pre-bog settling tank? My husband is imagining a box somewhere outside both pond and bog; we'd pump from the pond to the bottom of the box and let the water filter up through some media and trickle out the top where it gets fed to the pipe in the bog. I fear that there wont be enough time in the tank to get any significant settling, or we'd filter out too much.
Any thoughts or recommendations? Thank you!

 

[Jhn]

A couple things, as you surmised planted bogs don’t work if the plants get eaten.
Having perforated pipes on one side of the bog only, won’t work what will happen is it will come up only there and as the bogs gets packed with roots and gunk, it will channel over the surface of the rest of the bog, so that part of the bog will lose a great deal of effectiveness.

As for settling tanks you want the inflow pipe at the top of the tank and outflow up high as well otherwise solids won’t settle out but just flow through. Also pump shouldn’t be on pond bottom if it is.

 

[allif]

Having perforated pipes on one side of the bog only, won’t work what will happen is it will come up only there and as the bogs gets packed with roots and gunk, it will channel over the surface of the rest of the bog, so that part of the bog will lose a great deal of effectiveness.

Ah ok, I can see that now. Thank you

As for settling tanks you want the inflow pipe at the top of the tank and outflow up high as well otherwise solids won’t settle out but just flow through.

I still can't visualize this but ok. I was just looking at this setup on the Matala BioSteps filter. Wonder if we'd get too much bio filtration if we use that one?

Also pump shouldn’t be on pond bottom if it is.

It's not, but thanks for pointing that out.