Wetland Filter

[Pondfun]

I have enlarged my fish pond 3 times over the past 25 years. Now this will be the 4th time. I am adding a 20 x 23 foot addition to the pond. Deepest part is 4 1/2 feet deep. I am going to have an intake bay and a wetland filter. and two waterfalls. I am using 10 foot ABS 6 inch pipe for the centipide and reinforced milk milk creates for the blocks. The ABS pipe has cutouts at the top on both sides of the pipe every 5 inches apart, 1 inch wide and 4 1/2 long for water flow into the wetland filter. I will be using 3 sizes of stone gravel 8 inches of 3 - 6 inch stone, 8 inches of 2-3 inch and 8 inches of 3/4 - 1 1/2 inch stone. I will also have a pipe for cleanout. The size of the wetland will be about 15 feet x 4 feet by 3 feet deep. Plants will be planted also for filtration. I attached some photos of my project. That whole area will be the pond. The deep part is in the middle.

 

[Mmathis]

Hello and welcome! You will love your wetlands filter!

 

[Pondfun]

Do you have to clean your bog once a year?

 

[Mmathis]

Do you have to clean your bog once a year?

You may have to thin plants, but there is no “cleaning“ necessary for a bog/wetlands filter.

 

[Lisak1]

You've got it under control there! Looks good.

The only thing that occurred to me looking at your set up - is one run of 6 inch pipe going to be enough? Your bog is 4 feet wide - will that single piece of pipe distribute water completely through the width of they bog, or will it push only up through the middle? I guess that's the purpose of the blocks, too though - distribute the water more evenly across the surface.

I'm sure you've thought of this - just my early morning brain!

 

[Lisak1]

Do you have to clean your bog once a year?

I'll add on to what @Mmathis just said - I have personally never had to clean my bog in 8 years of constant use. I know some folks DO have the ability to flush it out and they do perform a back wash of sorts, but the few times we have checked ours via the vault, it's nothing but clean water. Plants - lots of pulling and thinning and keeping under control!

 

[Pondfun]

You've got it under control there! Looks good.

The only thing that occurred to me looking at your set up - is one run of 6 inch pipe going to be enough? Your bog is 4 feet wide - will that single piece of pipe distribute water completely through the width of they bog, or will it push only up through the middle? I guess that's the purpose of the blocks, too though - distribute the water more evenly across the surface.

I'm sure you've thought of this - just my early morning brain!

It is really 3 feet wide the extra space is for back filling the blocks with rocks. 6 inches on both sides of the blocks.

 

[Lisak1]

Well, if the backfill rocks are on the inside of the liner, then the bog is still four feet wide. Most bogs are constructed with a manifold that fills the bottom more completely. Yours will just run right up the middle, if I'm understanding correctly.

 

[Pondfun]

Well, if the backfill rocks are on the inside of the liner, then the bog is still four feet wide. Most bogs are constructed with a manifold that fills the bottom more completely. Yours will just run right up the middle, if I'm understanding correctly.

You always have to back fill the blocks so they are stable. On top of the blocks is the gravel you will have an extra 6 inches of gravel on both sides of the blocks. The water will come up though the blocks and fill the area even the 6 inches on both sides. Remember the blocks have holes on both sides so water will come though on the left and the right of the blog. The centipede pipe is in the center. The blocks are centered over the centipede. You always need more space in your wetland filter to set stones on the perimeter on the surface of the wetland. You want to have room for putting boulders. If you go to this link there is a photo of rocks that are outside of the blocks and centipede this is why there should be room for boulders outside of the wetland blocks and centipede. Also water always spreads out up and to the left and right as long as you have a slow flow. The flow is very important. http://www.landvistaaquascapes.com/blog/wetland-filters OK I also enclosed a photo below. You will see a space between the Aqua Blocks and liner. Anyway trying to make a clearer picture for you so you know what I am doing. Thanks

 

[Lisak1]

@Pondfun - I have a bog. I'm aware of how they work and how they are constructed. I won't disagree that you backfill the blocks for stability, however we backfilled outside the liner with sand, so in our case the backfilled area is not part of the bog. I was replying to your comment that your bog was only 3 feet wide - anything inside the liner is part of the bog, whether it's blocks or gravel, so subtracting your backfill gravel areas from your total width didn't make sense.

My concern was that your centipede is only filling a small six inch wide run at the bottom of your bog, pushing the water up only through the middle. Most bogs are constructed to diffuse the water more completely over the bottom of the bog so it percolates up from side to side, and back to front. You've got the back to front covered, but I'm not so sure about the side to side. Will the blocks create the diffusion? Perhaps. I guess time will tell. You seem confident, so I will leave it at that.

 

[poconojoe]

Kudos for taking the wetland/bog filter approach, you won't regret it.
Adding the bog to my pond was the ultimate best thing I ever did for my pond.
You will enjoy the benefits of maintenance free filtration and crystal clear water.

 

[Pondfun]

@Pondfun - I have a bog. I'm aware of how they work and how they are constructed. I won't disagree that you backfill the blocks for stability, however we backfilled outside the liner with sand, so in our case the backfilled area is not part of the bog. I was replying to your comment that your bog was only 3 feet wide - anything inside the liner is part of the bog, whether it's blocks or gravel, so subtracting your backfill gravel areas from your total width didn't make sense.

My concern was that your centipede is only filling a small six inch wide run at the bottom of your bog, pushing the water up only through the middle. Most bogs are constructed to diffuse the water more completely over the bottom of the bog so it percolates up from side to side, and back to front. You've got the back to front covered, but I'm not so sure about the side to side. Will the blocks create the diffusion? Perhaps. I guess time will tell. You seem confident, so I will leave it at that.

Thanks for getting back I have faith the water will diffuse the same way as the bought Aqua Blocks. The Milk Creates work the same way if done correctly. Same principle. Here is a link but these people did not use any blocks at all. The ABS pipe has cut outs every 5 inches on the top left and right of the pipe so the water will spread up the blocks left and right. http://www.bogfiltration.com/making_your_own_upflow_bog_filte.html

 

[Lisak1]

Let me try one more time... not trying to be ornery or nosy, just want to make sure I'm being clear.

The blocks are not the concern (although, the milk crate idea is still an open debate here as to how much weight they can hold, but that's another conversation) - the concern I have is the manifold. Your pipe running right down the middle of the bog is not a standard set up. Most builds have multiple runs, not one single run. That's all I'm trying to convey - will that work to move water equally through the whole bog? Or will it just push water up through the middle?

Here's a couple of examples from this forum - someone else drew these, so they aren't mine, but just for illustration of what I'm talking about:

There's definitely a difference when you run water through those "arms" versus just right up the middle. The question is - will it matter?

We actually used an Aquascape centipede for our manifold. It looks similar to this:

So while we don't have the "arms" we have water flow from all but the bottom of the unit. Perhaps yours will function the same way.

 

[Jhn]

I upgraded/enlarged my bog recently to the centipede snorkel style as my pond Is getting over populated. And figured just in case I need to clean it might as well make it as easy as possible.

I will say no matter the size of the wetland filter it helps, but if you are building a large pond and it gets overpopulated with fish that get large like most, I would shoot to make the bog the roughly recommended 30% of the pond surface area If possible. Is this pond going to be attached to your existing pond/s and the only filter for the pond, either way the bog is undersized for the size pond you are building. Unless you like to tinker and add things which it seems like you do, then you can just plan for your next addition to be another bog.

 

[brokensword]

Let me try one more time... not trying to be ornery or nosy, just want to make sure I'm being clear.

The blocks are not the concern (although, the milk crate idea is still an open debate here as to how much weight they can hold, but that's another conversation) - the concern I have is the manifold. Your pipe running right down the middle of the bog is not a standard set up. Most builds have multiple runs, not one single run. That's all I'm trying to convey - will that work to move water equally through the whole bog? Or will it just push water up through the middle?

Here's a couple of examples from this forum - someone else drew these, so they aren't mine, but just for illustration of what I'm talking about:

View attachment 135724View attachment 135725

There's definitely a difference when you run water through those "arms" versus just right up the middle. The question is - will it matter?

We actually used an Aquascape centipede for our manifold. It looks similar to this:

View attachment 135726

So while we don't have the "arms" we have water flow from all but the bottom of the unit. Perhaps yours will function the same way.

Lisa; while I'm also following your logic, imo, it won't matter. Consider; the water is forced (up,sideways, down--we've all done this water exit thing in different ways) out and like the saying 'water finds the path of least resistance' goes, the water then hits whatever barrier is first. If pointed up (the manifold), the water hits the aquablox first (after spreading out side to side as that is the way of least resistance) and then rising, the first layer of rock (if graduated. If not, then the pea gravel). This barrier provides the next level of resistance and again, water will seek the least path. So no matter that the pump is 'forcing', the water will flow into the easiest areas. It's not until there's pressure coming back from the above barriers does it then find other ways. If the water only was forced upward in a single direction, roots wouldn't bother the flow and you'd have no channeling. But it happens. Just like the roots, the rocks will be the resistance. Down below, any open space will be the first filling, then the next larger open areas (like between large rocks, as I have) and once past, into the next layer, same philosophy.

So, imo, unless you have the pea gravel all the way down, as long as you have open areas be it via aquablox or large boulders/stones, the water will distribute more or less evenly. And, as the above easy channels get clogged in any way, the water will be forced into those that are not, thus changing the upward path again.



JMHO