Broken bog manifold pipe!

[mrsclem]

I have had problems with my bog overflowing so removed the top board and moved liner up. Still lost water due to holes in liner where it was fastened. Now water is coming up thru the gravel a foot from the intake. I opened the cleanout pipe and no water is coming out so guess the manifold is broken. I made the mistake of using 1 1/2" pvc instead of 2". Now looking at tearing out the entire manifold and replacing it with 2" which I have on hand. Looked at replacing liner- Yikes! Ordered a 3"x25' patch material. Now I just need to dig out several thousand pounds of pea gravel! Planning on adding an additional 2x2 on the top to stop the overflow issue.
Will post pics and updates. Warning- if building a bog and you are planning on walking on it, use 2" pipe!

 

[addy1]

Bummer! I walk on mine all of the time, 2 inch pipes but buried 2.5 feet under gravel. Well protected.

 

[poconojoe]

I made the mistake of using 1 1/2" pvc instead of 2". Warning- if building a bog and you are planning on walking on it, use 2" pipe!

I can't see 2" pvc being any stronger than
1-1/2" pvc.
I would compare the thickness of the walls of each.

Make sure it's schedule 40.
Or if you want stronger, go with schedule 80.

 

[Tula]

Out manifold broke and it was 2 inch PVC and we never walked on it

 

[mrsclem]

Any idea why? I just assumed that walking on the bog caused the pipe to break.

 

[poconojoe]

Are you all using schedule 40 PVC?
That stuff is pretty strong. I think I could jump up and down on it all day long and I don't think it would even budge.

Or maybe the weak point is at the joints?
I'm guessing that could be the problem.

I'm no plumber, but there's a thinner walled PVC that is used for conditions that have no water pressure. I don't know what it's called, but I've seen it at the big box home centers.

Like I said previously, use schedule 80 if you feel the need.

 

[mrsclem]

Pretty sure what I have for 2" is schedule 40. I'm not sure about the pipe that broke. I may have cut thru too far in that section. Will see when I dig it up!

 

[poconojoe]

I may have cut thru too far in that section. Will see when I dig it up!

Ah, how stupid of me.
I forgot about the slits that we cut in our manifolds. Duh!
Yeah, those slits have to be weakening the pipe.
That's a good point to bring up for future builds.
I guess we have to be careful not to cut too deep and also not too close together.
I made the slits 1-1/2" apart. They probably should be further apart.

 

[SoCal Pond]

Just for reference I only have 3/4" PVC for my manifolds. My bog is only 300 gallons. I have two 600-900GPH pumps, one for each manifold.

Instead of slits I drilled 1/2" holes 4" apart crossing between sideways and up and down all the way.

The grids vary but are about 2 x 3' and 2 x 4' wide. Where the pipes enter the bog I used flex pipe to an air flow diverter to keep the water from siphoning the bog when the pumps are turned off. They work better than expected. Then more flex to the manifolds.

It is simple. When the pump turns on it might shoot a little water out but then goes down to the manifold. When turned off they suck up air and leave the water in the raised bog.

The bottoms of them are now covered in gravel. This was just for a picture.

 

[Lisak1]

@poconojoe - I was thinking the same thing! How in the world… and then it hit me - the slits!
Too many, too deep, or too close together could all contribute to weakening the pipe for sure.

@SoCal Pond may be on to something!

 

[Tula]

Any idea why? I just assumed that walking on the bog caused the pipe to break.

From what I've read and a few pictures I've seen, I believe our "break " ( almost appeared melted ) was caused by friction. I'm guessing the friction was caused by too much water pressure, perhaps too powerful a pump. I've also wondered if our pump pulled too many solids into the bog causing greater resistance.

We had the pump in the pond about 10 inches down from the water's surface. Whatever we did....it didn't work....we're "bog failures !!"

 

[GBBUDD]

The size and type of pipe can be totally irrelevant . A buried pipe is just like a culvert pipe that allows water to flow through it and has a foot or more gravel over it.
The foot of gravel will allow a pickup truck to cross over the pipe at a 90 degree . Double that thickness and a loaded 18 wheel truck could drive across. The earth works like a pyramid disbursing the weight evenly out and accross the area

The slits being cut and too often into the pvc certainly will compromise the pipe. However if your careful and you place the gravel carefully you could have cut them into individual pieces and once the gravel is packed around the pipe expecialy a foot of peastone you could jump up and down on the pile for hours and not get any weight down to the pipe..
Inmo slits every 1 1/2" is a tad over kill if you add up the volume of the amount of cuts and look at the size pipe your using its probably a good 15 times larger than is the opening of the pipe..
Yes we want the slits closer together so the water is disbursed evening across the bog but I'd prefer to cut the slits 6 inches apart and only cut 1/3 trough the pipe. But what I would do is make double cuts so the slit is at least 1/8 wide as most saw blades today aren't even a 1/8 wide.
Making sure the bottom of the bog Is relatively flat and even helps not flex the pipe. Also I would start with a larger rock of 1 to 2 inch around the pipe this will help protect the pipe from peastone getting to the slits.

One last comment if you have three pipe that will be in the manifold duct tape them flat together on a table . and cut across all three at once.

I just rebuilt my bog because I wanted more waterfall and yes what a pain. I even had an excavator. To dig down but I could not reach the bottom as it was 7 feet down and access was limited. But what I did find to be very handy was the shop vac. And I didn't have peastone mine was mostly 3/4 . Put the shop vac where you want to make a pile and when it fills just tip it over.
If you can try to keep an area constantly wet so when you rebuild the bog you can place a layer of the old peastone toward the bottom of the new bog so your seeding the new bog with your old bacteria that took years to grow.

 

[mrsclem]

Some very good ideas here! Going to shovel first then may try the shop vac. Love the idea of taping the pipes to cut them.
Some say slits up, some say down. Any reason you couldn't do on the sides or even alternate 1up & 1 down??

 

[GBBUDD]

I am cut down UNLESS you start with a layer of larger rocks first as I mentioned above. Then cut up . My main reason cut down was to use every inch or rock as quick as possible within the bog. The larger rock will allow similar to happen

 

[poconojoe]

Just for reference I only have 3/4" PVC for my manifolds. My bog is only 300 gallons. I have two 600-900GPH pumps, one for each manifold.

Instead of slits I drilled 1/2" holes 4" apart crossing between sideways and up and down all the way.

The grids vary but are about 2 x 3' and 2 x 4' wide. Where the pipes enter the bog I used flex pipe to an air flow diverter to keep the water from siphoning the bog when the pumps are turned off. They work better than expected. Then more flex to the manifolds.

It is simple. When the pump turns on it might shoot a little water out but then goes down to the manifold. When turned off they suck up air and leave the water in the raised bog.

The bottoms of them are now covered in gravel. This was just for a picture.

View attachment 153969

I'm not sure what you have there.
Maybe you can describe it again.

What I did as a vacuum break was to add a spitter statue to my bog feed pipe.
When the pump is running, the water flows out of the spitter statue, as normal. If the pump turns off, water retracts backwards out of the spitter and then it pulls in air, breaking the backward flow of water out of the bog.