Operation Duck pond is a go! Phase 1: pre-planning

[brokensword]

Excellent! That is a great reply. I didn't realize that even suspended solids would be considered "solids". I was thinking solids referred to sticks/leaves that fall in and can damage a pump.

As of now, I am planning to make my bog almost 80% the size of my pond, so I am really hoping that will speed up the processing of all the duck's solids.

I am also hoping that I can make my bog deep, with a nice void under the pea-gravel to allow those solids to settle a bit. I also plan on having a large enough cleanout connected to the bog dispersion pipe, so all the muck vacuum/pumping can take place at that point. I saw something here suggesting some water jets that would help break up the solids that settle out to allow the pump to continue to move those contaminants to the bog for filtration. Not sure how that would work with having a pump in the pond, vs in a skimmer/intake bay. What are your opinions on intake bays? I am concerned a bit that the intake bay or skimmer will only let surface level water into the pump, and all the duck waste will accumulate on the pond's floor. But maybe that's not such a bad thing?

My main design principles are: simplicity, and clean aesthetics. So I am attempting to contain all my filtering/pumping/cleaning/etc within the confines of the pond itself.

I hear you re simplicity; it's why many of my improvements in my expansion were made. Rinsing pads of any kind gets old after a while, especially when if done right, the bog can handle it with only thinning of plants as maintenance.

I don't think I'd disturb your pond with jets (to stir stuff up) as I'd rather have the water column clear for visual pleasure. Jets will make this less likely and I'd also rather have the solids more easily removable via pool net. Having an easy accessed cleanout on your bog will do you well. As will such a large surface area. I too made my bog deeper as well at 3'. Don't use much more than 12" of pea gravel, imo, as the smaller particles will clog faster with more resistance from over top. I used 3 stages; large 8" round stone on the bottom, then 2" cobble, followed by the 12" of pea gravel. Use ALL rounded stone, nothing with an edge as you don't want your bog stone to crush together, which sharp-edged stone will do over time.

Another note re your bog design; cleanout should be at the deepest part of your bog with both walls and floor angling down to this point. The idea, should you need it, is to backflush with something strong like a pond pump, the surface of your bog so any clogging debris drops down and flows toward your cleanout where another pump waits to clear it out. A pond professional told me it usually takes 2-3 times of backflush to see clear water only. The idea, hopefully, is that you'll not ever have to do this and that nature will decompse any organics at the bottom/between stones of your bog before it becomes an issue. Hence why you try not to send any solids to the bog in the first place.

An intake bay is a neat idea but is mainly going to help with floating debris. I doubt this is the type of mess your ducks will make, so plan accordingly relative to what trees/pollen sources you have near the pond. Same with a skimmer. I'd imagine the mess ducks will make is more organic through their excrement than anything else. With enough plants and such a large bog, unless you over stock on ducks (along with feeding them), it sounds like you'll be fine. Just monitor, do some water tests, etc until you find the balance you need. It'll take a bit of time for your bog to flourish; you can help by planting a lot of shallow rooted, fast-growing plants like creeping jenny, pennywort, parrot's feather, forget-me-nots. For the pond proper, water lettuce and water hyacinth will do well, though I don't know if your ducks will find they're salad material!



Hope this helps!

 

[nimrod]

Thanks Brokensword!
I have noted your tips on bog creation, and that is indeed my plan to have the bog-sump in the lowest spot in the bog. I like the idea of having 3 layers of different size stone, but my situation is somewhat unique as I don't have machine access to my back yard. So all the stone I plan to install is going to be moved by yours truly... Those pricey aquablocks are looking more appealing by the minute!

As far as skimmers/intake bays are concerned: I haven't really seen any good design diagrams or videos on constructing an intake bay. Most I have seen simply resemble bog filters, but with the pump at the bottom. The surface debris in my planned location is not much, but we do intend on planting lots of stuff near the pond, and I can see that assessment changing, so I am trying to avoid another pond project in 2-3 years (wishful thinking, I know ) Also the ducks tend to groom themselves in the pond, leaving behind feathers that have a tendency to block the draining of their existing "pond", so I guess I think that might be good enough reason for the skimmer/bay. Especially if it's not tremendously complicated to do.

I really appreciate your well thought out responses, and it helps to have a sounding board when doing the design of these things. I can get carried away, and the wife is only interested in hearing about water filtration for a limited amount of time!

 

[nimrod]

They are still solid 10 years later.

yes but right now the deer have knocked most of it into the pond on the bog shelf wall. Once warmer I will stick my arms in and pull it out.

While doing some research into the best way to build this separator using landscape timber, I came across "earthbag" building. Basically using sandbags full of sand or dirt to build retaining walls. This is pretty appealing, because it's cheaper, and can be used to build a curved wall. If I make the wall sturdy enough, do you see any issue with using sandbags full of dirt as the divider under the liner?

 

[brokensword]

While doing some research into the best way to build this separator using landscape timber, I came across "earthbag" building. Basically using sandbags full of sand or dirt to build retaining walls. This is pretty appealing, because it's cheaper, and can be used to build a curved wall. If I make the wall sturdy enough, do you see any issue with using sandbags full of dirt as the divider under the liner?

It should work, imo, with an eye toward making sure this wall won't tip/lean outward and collapse. A sandbag (I'd not use dirt; you'd be adding potential debri/mess to your pond) would be a large rock in its way, so you're building a rock wall. There will probably be some water transfer between pond and bog but I don't see it as a problem as most of the water will push up through the 'easier-to-penetrate' substrate of rocks and gravel. In time, I imagine the sandbag wall would clog up to some extent and you'd have less transfer. I've not done a bog this way, but those are my thoughts.

What I did was to use a single liner for both bog and pond. My bog is dug down about 2' or so below the pond surface while another 12" lies above. I built from ground-contact treated 4x4s a box and this is what holds all my gravel/pipes/liner. If you have the option, you could do this instead of your sandbags, thereby knowing you have the pond holding the box on one side and the bog stone on the other with more construction surety. This also allows you to shape the 'box' any way you want. You'd dig a shelf then, 12" or so below pond height and use this as your platform/base for your bog box.

Just an idea.

 

[GBBUDD]

1. Will a 40% bog be enough to filter out all my duck’s waste? These guys poop a lot! recomended is 30% but i am a huge fan of over filtering and with ducks your heading in the right direction.
2. Most of the builds I have been looking at have a pump that sits off the floor of the pond, or in a skimmer box/negative edge… What happens to all the sludge that collects on the floor of the pool? . I myself would make the bottom as rounded as i could while ducks do not need 6 feet in depth by any means if you have the bottom like a champain glass where all the poop was directed toward the very bottom a main drain system which almost always requires two by code/ law the wase will get pulled into the drain and sent to the bog .
3. Should I use some sort of solids filter (radial flow, or swirl)? My preference is obviously not to have yet another filter in addition to the bog. Do you use a second pump for that, or can I split the flow? It is my understanding that the key to a good solids filter is retention time, so if I would need to slow the flow down somehow?
4. Do I need a skimmer? With the feathers and other sticks twigs and hitch hikers they drag in to the pond i would .
5. The barrier wall between bog and pond… what’s the best way to build this? Under the liner with cinder blocks? Just dig out the two halves of the circular plan? People usually build three ponds big bigger and biggest i went to the end result on my first and love love love it. I can see the draw for many or circular ponds but to have both be circular and one cuts into the other i just don't see . i'd go for your round in the duck pond then the bog i would make what ever shape i could with all the left over liner i had left . but my taste' is more of a naturalist then it is contemporary. Easiest is probably both in the same liner. but be very cautious if sharp edges on the rubber. rounding cinderblock edges before they go in the pond with a simple grinder. and building the wall on many layers of fabric of underlayment. or on a bed of sand but the sand has to be where it can not just slip out and away.

 

[GBBUDD]

The bog WILL break down the solids as well as the ones-you-can't but it takes more time and these solids can constrict the flow up from the bottom of the bog. This is called clogging. When this happens, the water finds other ways to rise and thus avoids a lot of the bacteria-colonized gravel in your bog, thus circumventing

That is one advantage to the snorkel and centipede systems tot he aquablock bogs . The water is pumped into the centipede this is a large area about 18" wide and a foot tall or there about . the water flow is reduced due to the size of area and is open to the aqua blocks above. This is where the water flow is reduced even more . the goal is to have this area replaced by displacement more then by displacement by noticeable flow and with all the dividers and such within the aquablocks odds are these fragments will be come condominiums for bacteria and a hole host of other creatures as they eat it up. . Then the left overs might make there way to the gravel above but it's there we hope the design works to where the debris falls back to the centipede and to the clean out chamber of the snorkel. or as mentioned above it will find the path of least resistance as it works its way up through the rock and roots of the wetland plants

 

[GBBUDD]

Excellent explanation of why a aquablox wetland filter works as good as it does and how to design and build a pond

The first video has Ed explaining just why a Aquabox bog works in my honest opinion the best https://www.youtube.com/watch?v=HimBE7xSr5M This video has a guide as to how large a wetland filter should be , by the Square footage of your pond. He also gets into the nuts and bolts of...

www.gardenpondforum.com

 

[nimrod]

It should work, imo, with an eye toward making sure this wall won't tip/lean outward and collapse. A sandbag (I'd not use dirt; you'd be adding potential debri/mess to your pond) would be a large rock in its way, so you're building a rock wall. There will probably be some water transfer between pond and bog but I don't see it as a problem as most of the water will push up through the 'easier-to-penetrate' substrate of rocks and gravel. In time, I imagine the sandbag wall would clog up to some extent and you'd have less transfer. I've not done a bog this way, but those are my thoughts.

What I did was to use a single liner for both bog and pond. My bog is dug down about 2' or so below the pond surface while another 12" lies above. I built from ground-contact treated 4x4s a box and this is what holds all my gravel/pipes/liner. If you have the option, you could do this instead of your sandbags, thereby knowing you have the pond holding the box on one side and the bog stone on the other with more construction surety. This also allows you to shape the 'box' any way you want. You'd dig a shelf then, 12" or so below pond height and use this as your platform/base for your bog box.

Just an idea.

I see that I was not clear enough in my explaination! My intent was not to put the sandbags INSIDE the pond, but under the liner. Similar to how addy had done with the landscaping timber. I was drawn to the sandbag option because of the ability to create a less angular divider (and price!) I am hoping that with a wall that is only 3ish feet tall, it will be stable enough with water of the pond on one side, and bog gravel on the other side. I've seen some things where people reinforce "earthbag" walls using rebar stakes driven through them into the ground, so I am not afraid to pursue that avenue as well.

 

[GBBUDD]

There are sand bags and there are sand tubes , with enough rebar even the tubes would work With out i would not temp it 3 feet is not a ton of weight pushing at the dividing wall but if you do use pea stone it has properties like sand there will be enough pressure to push over tubes with little doubt.

 

[nimrod]

There are sand bags and there are sand tubes , with enough rebar even the tubes would work With out i would not temp it 3 feet is not a ton of weight pushing at the dividing wall but if you do use pea stone it has properties like sand there will be enough pressure to push over tubes with little doubt.

I intend to get the sandbags that they use for holding back floodwater. I figure that's precisely what they'll be doing!

 

[brokensword]

I see that I was not clear enough in my explaination! My intent was not to put the sandbags INSIDE the pond, but under the liner. Similar to how addy had done with the landscaping timber. I was drawn to the sandbag option because of the ability to create a less angular divider (and price!) I am hoping that with a wall that is only 3ish feet tall, it will be stable enough with water of the pond on one side, and bog gravel on the other side. I've seen some things where people reinforce "earthbag" walls using rebar stakes driven through them into the ground, so I am not afraid to pursue that avenue as well.

seems to me if you make this wall-beneath-the-liner concave on both sides, I can't see it being a problem. (and you want this shape for the inside of your bog anyhow) As opposed to stacking straight up, which to me would be a concern. And maybe rebar has been used to help support but I'd probably avoid anything which might accidently come in contact with my liner, creating a hole/leak. Just me though--I'm the type now that has all the water lines INSIDE the liner just so there's zero percent chance of emptying the pond by accident.

 

[GBBUDD]

I myself would use caution the stakes could end up puncturing the liner as sand bags can even compress there kinda hard to compact. i would probably go as far as to 1. not have it in the top bag or two cap the sand bags with some wood . The pressures at the top of the pond are minimal

 

[addy1]

We put rebar through the landscape timbers, put a cement tube at each end of the bog with the timbers on the bog side of the cement. It has never moved.

 

[west]

Hey everyone - my name is West and I am new here! I am looking to build a duck pond with a large bog filter just like @nimrod described.

Any recent updates on the build @nimrod?

 

[GBBUDD]

Welcome. Forget the pond give them a sprinkler on a motion sensor