Hamstermann's pond build

[Lisak1]

Just catching up here... sorry I missed the party on getting the rocks in the pond. We started out very carefully when we were rocking and then at some point it was just "bombs away! " as we rolled them down the side of the pond using the area that later became my "steps". I prayed for my liner that whole day - not a rip or a tear anywhere. So watch for sharp edges, but smooth, round granite rocks won't hurt a thing.

That soft underfoot plant you're looking for is algae - our whole pond interior is covered in carpet algae. Took about a season or two, but it's now firmly affixed, bright green, soft underfoot and really stops the slippery issues I had in the beginning climbing in and out of the pond.

We do have floating hearts that have established themselves in the pond - kind of like tiny water lilies that grow up from he bottom. Very cool to watch the fish dart in and out of them and the tiny pads float on top just like a lily. And they are easy to yank out when they move into areas where I don't necessarily want them. Not sure how they would hold up to regular swimming.

 

[hamstermann]

Thanks, @Lisak1 !

Actually you didn't miss the rocking. I just started it today. I spent a lot longer than I expected (3 hours or so, I think) carefully sawing slots in the half-pipe I have for my centipede:

Then my sons and I put another layer of geotextile on the liner in the bog area and my sons picked through the rock pile to find rocks to put in around the centipede to weight it down:

and we cut an archway-ish shaped hole in some more pipe to be a snorkel and got that in place:

It was about this time that I realized I'd made a mistake in my planning. originally I had the bog at 50% of the pond, but when I had the excavator I decided that was too big and I wanted more room for the pond, so I took out the wall that I'd left to separate the two. My thought was to build a rock wall and move it further east for a 5.5 or so foot bog instead of a 10. I was inspired by this video by columbia water gardens:

My mistake though was that in an intake bay, you can use 3/4 stone on the bottom of the area because the water flows in and to the pumps, making it kind of a down-flow bog. I'm building an up-flow bog which requires bigger rock around the centipede and is harder to level to put the aquabocks (or in my case, milk crates) on securely so we can lock them together horizontally and keep everything even.

Also, I was assuming I could get the liner on the bottom of the pond wrinkle-free and seam a liner to it to lean against the milkcrates and behind the rock wall, kind of like this:

There is no getting the liner wrinkle-free in that area and I don't think I can successfully seam the vertical liner to the horizontal one around the wrinkles and have everything be water-tight. I'm also realizing now that takes a herculean effort of balancing opposing forces with the milk crates, the rocks under them, all the extra layers of geotextile and fabric, etc.

So now I'm wondering if instead of 3/4 stone under the milk crates like we would in an intake bay, if I used 2-4 inch cobbles (instead of the 4-8s that Aquascape recommends), will that be a good compromise and still level and pack well enough to let the milk crates all stay coplanar but also have big enough openings between the rocks to allow good cleanouts and good waterflow through the centipede? And if I just skip the liner and geotextile layers between the milk crates and larger boulders(the orange line and the green on both sides of it) and mortar the boulders together with either mortar or foam so it's all one unit, will that be water proof enough to still force the bog water up through the milk crates? I know both foam and mortar can be porous but I'm hoping that won't matter as munch underwater if water really does just take the easiest route and go up instead. I'm also hoping if I stack the boulders tight enough that I won't need a ton of mortar or foam and it won't fall on anyone, trapping them.

Another thought I had to solve the issue was to put maybe a couple layers of geotextile on the pond bottom liner then build a cinder block wall on top of them - that would be easier to stack than natural rock, but there's no trench there and I am most definitely NOT removing the liner to dig another trench, thereby undoing the work I've done with the centipede and retaining wall trench against the patio. so the cinder block wall would be unsteady and scary. so that plan's out.

I could also stack things like this, maybe:

Leaving out the gravel under the milk crates seems like a bad plan because it would be hard to keep the milk crates all level once we get over the centipede. It also throws a wrench in things to have large enough cobble under the milk crates for the bog to work right and then try to level it to put milk crates on top of it and a liner (loose or seamed) under the cobble. What I do like about this design though is that by having a single level of milk crates backed up against a double level, we can have artificial shelves which will make it easier to stack rock and have things maybe look a bit more natural.

What thoughts do you all have about either of these solutions? Or do you have another suggestion on how to handle it?

I guess another option would be to scrap the whole bog idea and just put a biofalls in the corner opposite the intake bay, but since part of the point of building this was so that I could try growing things in the bog, I don't want to do that.

 

[YShahar]

Another thought I had to solve the issue was to put maybe a couple layers of geotextile on the pond bottom liner then build a cinder block wall on top of them - that would be easier to stack than natural rock, but there's no trench there and I am most definitely NOT removing the liner to dig another trench, thereby undoing the work I've done with the centipede and retaining wall trench against the patio. so the cinder block wall would be unsteady and scary. so that plan's out.

I think I'm confused as to what the problem is that you're trying to solve. Is the issue how to move water from the bog back into the pond? Or is is how to level up the milk crates inside the bog?

Leaving out the gravel under the milk crates seems like a bad plan because it would be hard to keep the milk crates all level once we get over the centipede. It also throws a wrench in things to have large enough cobble under the milk crates for the bog to work right and then try to level it to put milk crates on top of it and a liner (loose or seamed) under the cobble. What I do like about this design though is that by having a single level of milk crates backed up against a double level, we can have artificial shelves which will make it easier to stack rock and have things maybe look a bit more natural.

I had a sort of the same issue, in that it was nearly impossible to get the aquablocks / milk crates exactly level. So yes, I used river rock for that, having first used very fine gravel (and even paving stones) to build up the ground underneath the liner. We don't have soil here, so once the bog was dug up, the issue was building up around the centipede. Once the level was as near as I could get it, I used river rock under the milk crates.

What thoughts do you all have about either of these solutions? Or do you have another suggestion on how to handle it?

I guess another option would be to scrap the whole bog idea and just put a biofalls in the corner opposite the intake bay, but since part of the point of building this was so that I could try growing things in the bog, I don't want to do that.

I definitely wouldn't scrap the bog! But I think I'm still confused as to what the problem is that you're facing.

 

[hamstermann]

I think I'm confused as to what the problem is that you're trying to solve.

Sorry about that! There are 2 problems, really. The first one is how to build a stable wall on top of the existing liner that will divide the pond from the bog without having to pull up the liner and dig a trench. The second one is what size rock to use in the bog so that I can get the milk crates level, secure, and tight, but still have large enough spaces between the rocks that sit between the milk crates and centipede that the bog will work properly and still be easy to backflush.

I had a sort of the same issue, in that it was nearly impossible to get the aquablocks / milk crates exactly level. So yes, I used river rock for that, having first used very fine gravel (and even paving stones) to build up the ground underneath the liner. We don't have soil here, so once the bog was dug up, the issue was building up around the centipede. Once the level was as near as I could get it, I used river rock under the milk crates.

Thanks. What size river rock did you use?

 

[YShahar]

Sorry about that! There are 2 problems, really. The first one is how to build a stable wall on top of the existing liner that will divide the pond from the bog without having to pull up the liner and dig a trench. The second one is what size rock to use in the bog so that I can get the milk crates level, secure, and tight, but still have large enough spaces between the rocks that sit between the milk crates and centipede that the bog will work properly and still be easy to backflush.

Aha! OK, got it. Do the bog and the pond use two separate liners? if so, you'll need to either seam the two liners, or raise the water level in the bog by 15-20 cm so you've got enough drop for an overlay. If you do that, then you can also design a natural looking flow.

If it's all one liner, then there are two possibilities:

1). Add soil underneath the place where they merge to make a division; or

2) Build a wall inside the liner using milk crates filled with stone, with a piece of underlayment wrapped around one or both sides. It won't be water-tight, but will at least keep the two bodies of water separated. I'm guessing that's something like what you had in mind in the diagrams above. You could use a piece of liner to make the wall, but unless you can seam it, it still won't be totally water-tight. I've seen roofers use a kind of gooey glue that bond even somewhat wrinkly bits of EPDM, but caulking might work as well. @GBBUDD could probably give you some better advice on that.

Thanks. What size river rock did you use?

Roughly 1.5 to 2 cm. diameter, with some flat rocks here and there to level things up.

 

[hamstermann]

If it's all one liner, then there are two possibilities:

1). Add soil underneath the place where they merge to make a division; or

2) Build a wall inside the liner using milk crates filled with stone, with a piece of underlayment wrapped around one or both sides. It won't be water-tight, but will at least keep the two bodies of water separated. I'm guessing that's something like what you had in mind in the diagrams above. You could use a piece of liner to make the wall, but unless you can seam it, it still won't be totally water-tight. I've seen roofers use a kind of gooey glue that bond even somewhat wrinkly bits of EPDM, but caulking might work as well. @GBBUDD could probably give you some better advice on that.

oh, I like the idea of filling milk crates with stone and putting liner and fabric around that and then caulking the edges. So simple and easy. Thanks! In my pictures I was thinking of leaving the milk crates for the wall empty so that they can add to the bog volume, but weighting the perimeter ones down with Rocks inside of them will not only make the wall more stable but allow me to use up some sharp rocks I was afraid to put directly on the liner and geotextile. That's genius!

Roughly 1.5 to 2 cm. diameter, with some flat rocks here and there to level things up.

Wow, that's 1/2 inch to 3/4 of an inch - much smaller than I thought! Are you still able to backflush for cleanouts when needed?

 

[GBBUDD]

The only time I can agree with caulking a joint is when it is a lap joint that's out of water. Yes there are some very sticky caulking out there but the primer and roll tapes works very well and it is quick.

What I do however is even beyond what I have seen any of the pros do. And that is to seam the underside of the liner with the primer and double sided tape then caulk the edges of the seam. So you now have three seals.

Then come back to the face of the liner and seam that. Caulk those edges then put side sided seam tape over those ages and caulk those. You now have so many seams that have to fail to get down to where you start leaking and when you have literally TONS of rock sitting on the liner underwater. The last thing you want is to go through the castles of finding the leak and removing all the stone then having to put it all back.

So for the sake of a little primer, double the amount of seam tape. And double the time which if you watch the videos it only takes a 30 minutes to seam a 25 foot seam.

As to the milk crates it's a great idea aquascapes did similar with aquablocks on a pool conversion. And here's why they had the bog under water / barely above the water line. So there was no pressure on one side more so than the other.

I know you had said you didn't want more than a six inch waterfall I still think that's a mistake. The energy used is the same for 6 inch as would a 18 inch . But the impact the already is tenfold.

But that's where the milk crates start to fail as they don t have much in side to side strength as the bog maybe lifted. Would a second row of milk crates solve this I'd would say yes. If the end of the pond is narrow enough that the milk crate wall was not just straight across that too if in the shape of a U then that could help stabilize the wall

 

[hamstermann]

If the end of the pond is narrow enough that the milk crate wall was not just straight across that too if in the shape of a U then that could help stabilize the wall

What would that look like? I would think that the milk crates would have to be straight to have the side-to-side support.

As to the milk crates it's a great idea aquascapes did similar with aquablocks on a pool conversion.

Do you know what the video was called, how long ago it was, or on what channel? I'd like to see that.

 

[GBBUDD]

It's one of team aquascapes pond conversions if I see it I'll post it.

 

[hamstermann]

It's one of team aquascapes pond conversions if I see it I'll post it.

Found it, I think.

 

[GBBUDD]

That's it

 

[GBBUDD]

What would that look like? I would think that the milk crates would have to be straight to have the side-to-side support.


Do you know what the video was called, how long ago it was, or on what channel? I'd like to see that.

When any wall reaches heights more than its base width it starts to become unstable against side pressures. tying the wall together milk crate to each other helps to stabilize but only by sheer mass so it takes more pressure to push it over . now place side walls in the front of the long wall and those act like a buttress making it almost impossible to topple

 

[hamstermann]

When any wall reaches heights more than its base width it starts to become unstable against side pressures. tying the wall together milk crate to each other helps to stabilize but only by sheer mass so it takes more pressure to push it over . now place side walls in the front of the long wall and those act like a buttress making it almost impossible to topple

Does it matter how long the "legs" of the u are? And can it be a block u that's basically just a square without the 4th side?

 

[GBBUDD]

lets start with the facts, how tall is the wall ? and how much taller is the bog from the pond

 

[GBBUDD]

While the tails / U ends stabilize the end wall they too can have the same issue on it's end. the idea is to have each lock in the last. Like i have said before these rocks are going to be exposed the youth climbing jumping and pulling on them everything needs to be locked in place . by pure size or by design like angled back so a rock would actually have to be lifted and not just tugged on. END GAME IS TO INSURE NO ONE CAN TOPPLE ROCKS OR WALLS AND HAVE THEM HOLD THEM UNDERWATER. Also keep in mind that those young boys if they are trying to catch a frog and while they are fast with a jump. they are not underwater and if it swims between rocks there's a good chance a small hand will follow, and we got to make sure they don't get stuck and held under water.