Minimizing plumbing/head pressure reduction/brainstorming

[DanielleB]

So I wanted to put my brainstorming ideas for the pond renovation out there and get some feedback on my 'very basic' plumbing. So first here are the shots of the old pond before removal of old 'liner' and my sketches of how to redo. I have pushed all the rocks off the old liner and got rid of it. Soil is actually silty sand so liner definitely needed. The big question I have is why I don't see more bogs with this top down/bottom up idea with flexible PVC tubing barely inside the cleanout vault so no siphoning affect . Not enough flow to the end of the bog? I really don't want to punch a hole in my liner to run tubing through and I want to get as much flow as possible into the bog. Fluid mechanics are not my strong point and neither is plumbing. I can drill holes fine but making attachments is usually what bites me in the end
Any input is appreciated. Thanks!

 

[TheFishGuy]

Are you looking at a centipede style bog? IE something like this:

 

[DanielleB]

Are you looking at a centipede style bog? IE something like this:

View attachment 149480

yes but a DIY style type. I figure septic leaching for the horizontal at the bottom and a the vault/cleanout from a trashcan or stacked valve boxes.

 

[combatwombat]

I think you have a really smart design putting your bog next to the intake bay, but keeping the flow of the pond running from one end to the other. That will really reduce head loss from piping. That can be mostly be overcome by using a larger pipe, though.

As for dumping into the top of the snorkel, that won’t work. The gravel in the bog exerts head pressure and the open space in the snorkel does not.

Water always tries to take the path of least resistance.That means most of your water will not go through the gravel. It will just dump out the top of the snorkel, almost completely bypassing filtration.

The water really needs to be fed to the bottom of the bog to force it through the gravel. Even then you will sometimes get channeling through the snorkel.

You can keep your current layout and still avoid siphoning by putting the snorkel at the other end of the bog and drilling a small hole in the pipe just above water line.

 

[bagsmom]

Danielle, have you checked out Ozponds on YouTube? I believe he has done a DIY version of a snorkel and centipede.

 

[poconojoe]

I'm not totally following you.

Upflow bog filters are just that. Water is pumped under the gravel usually through some form of distribution manifolds. Those manifolds spread out the water beneath the gravel. It then rises up through the gravel and returns to the pond.
I can see the percolation of the rising water on top of my gravel and it's very evident that it is spread very well throughout the bog.

You don't want the water to flow too fast through the bog.

You don't need to make any holes in the bog liner.
My feed goes over the wall from the pond to the bog. Most of the black flex PVC going over the wall is covered with the rocks on the wall. You can only see maybe 4-5 inches between the water surface and the rock wall. Plus it's black and not that noticable.

All of my plumbing is within the pond and bog. If there is ever a leak, it cannot escape the system.

You can go with the simple manifold covered with gravel, which works very well. Or for larger ponds you can go with a version of the snorkel and centipede.

 

[DanielleB]

So I was trying to think about the best way to get the flow from the intake to the bog while minimizing the increase in height and length the tubing had to travel. I know my current pump is under powered. And god only knows how long it'll take to get an electrician to run a line to the pond so I can run a better one.
I've watched through most of OZ ponds and bugger if I know where to get a olive barrel, LOL. But I also saw an aquascape bibbing techniques that I thought might work . I'm actually testing the theory out with legos and a dish towel, use what you've got, right?
I was thinking/wondering if anyone has use bibbing for a vertical waterblock? so a single piece of liner for the bog and intake with a small length rigid pvc in the trench between them. your run your flex pipe through capped pvc . You layer a scrap of liner and underlay down fill with sand to the height of the bog and intake to plug the top of the trench. and cover with rocks any small gaps could be filled with foam. The pressure would be pretty equal on both sides I would think. You could probably even seam the internal liner on both ends to reinforce the sand pocket and insure no leakage
Then later if I upgraded the pump and subsequently the tubing I would have to do anything except drain the two areas and drill bigger holes in the pvc endcaps.
and thinking about it further you wouldn't even necessarily need the sand bag if you laid the the pipe back filled and seam the edges together. I'll put down some drawings.it would mean a large liner but I think it would save trouble down the road.

 

[GBBUDD]

I want to get as much flow as possible into the bog

As for dumping into the top of the snorkel, that won’t work. The gravel in the bog exerts head pressure and the open space in the snorkel does not.

@combatwombat I'm not totally convinced that that is so. if you think about it Path of least resistance right? you pump to a centipede that is connected to a snorkel that's all OPEN. IN 5 YEARS MY bog never started to back up the water level inside the snorkel was the same as was in the outside of the snorkel . It may have been only an inch difference. so what does it matter if the water is dumped into the top of the snorkel or the end of the centipede. I was actually contemplating dumping water at the top of the snorkel have horizontal chambers so by the time the water got to centipede it had lost velocity and the sediment we try to collect at the bottom of the centipede was now already at the bottom of the snorkel. where we want it to be able to clean it out. the key is to have the snorkel sealed so the water still empties into the bottom of the matrix bog

what's stopping me from this theory is i AM NOT DOING THIS AGAIN

 

[GBBUDD]

sO NOW THAT I HAVE EVRYONE with there minds in a spin i am doing the feed to the end of the centipede and a cleanout snorkel on the opposite end. which is oposite of the first drawing but i believe is what you drew on the second but im not positive it's a bit confusing

 

[DanielleB]

yes snorkel at opposite of centipede to inflow of water. I was wondering if you could basically back fill the liner on either side to have it touching and come across the top of a pipe between the intake and the bog

 

[GBBUDD]

the rule is to feed the centipede on the opposite end of the snorkel . push sediment toward snorkel and use snorkel for yearly clean out . I have never seen a video of the opposite or a discussion.

 

[combatwombat]

the key is to have the snorkel sealed

That would, indeed, be the key.

 

[GBBUDD]

so if the snorkel has no leaks should it matter if you feed the centipede or the snorkel?

 

[combatwombat]

So I was trying to think about the best way to get the flow from the intake to the bog while minimizing the increase in height and length the tubing had to travel. I know my current pump is under powered. And god only knows how long it'll take to get an electrician to run a line to the pond so I can run a better one.
I've watched through most of OZ ponds and bugger if I know where to get a olive barrel, LOL. But I also saw an aquascape bibbing techniques that I thought might work . I'm actually testing the theory out with legos and a dish towel, use what you've got, right?
I was thinking/wondering if anyone has use bibbing for a vertical waterblock? so a single piece of liner for the bog and intake with a small length rigid pvc in the trench between them. your run your flex pipe through capped pvc . You layer a scrap of liner and underlay down fill with sand to the height of the bog and intake to plug the top of the trench. and cover with rocks any small gaps could be filled with foam. The pressure would be pretty equal on both sides I would think. You could probably even seam the internal liner on both ends to reinforce the sand pocket and insure no leakage
Then later if I upgraded the pump and subsequently the tubing I would have to do anything except drain the two areas and drill bigger holes in the pvc endcaps.
and thinking about it further you wouldn't even necessarily need the sand bag if you laid the the pipe back filled and seam the edges together. I'll put down some drawings.it would mean a large liner but I think it would save trouble down the road.

I think you're asking for trouble. I think I understand what you're after here: basically sleeving your pipe between the intake and the bog to keep the run short and the piping all below the water.

But how much are you actually gaining with that design? How much shorter will the pipe run be? What size pipe are you using (you probably mentioned this, but I forgot)? How high above pond water level will pipe have to rise to get over the bog liner? And what gph are you trying to push?

My gut says you could just go up 1/2" - 1" in pipe sizing and get the same result without the risk of inaccessible liner penetrations.

 

[combatwombat]

so if the snorkel has no leaks should it matter if you feed the centipede or the snorkel?

I don't think it would matter.