Bog pump vault / centipede

[Meyer Jordan]

I would think the pea gravel better because of more surface area and even if I have to back flush, would think the smaller gravel would keep the water column cleaner. I

You are thinking of the 'bog' as a mechanical filter and it should not be thought of this way. It should be considered as only a bio-filter. The water entering the 'bog' should be pre-filtered in some manner in order to keep the TSS to the lowest possible level. By not providing this pre-filtration the 'bog', depending on the water quality of the pond, will immediately begin to filter out these solids and in doing so also immediately begin to clog. The rate at which the 'bog' will clog is in direct relation to the TSS of the pond water.
This steady clogging of the 'bog' also progressively reduces any biological filtration that may be attainable with a clear system. This is one reason that I prefer the use of the matrix cubes. Coupled with a reduced flow rate any TSS that is not captured by the pre-filter is allowed to settle out before it reaches the gravel layer.
I feel that if I have to consider the 'bog' handling the bulk of mechanical filtration then somewhere there is a flaw in my design.

 

[brokensword]

Thanks, Meyer; I got it now. I'm hoping tomorrow to begin the plumbing of the new drum filter and set up exactly what you're suggesting.

 

[Gordo33]

centipede or diffuser pipe definitely needs to be countersunk

Is it necessary to have a diffuser pipe to distribute the water across the bog? If the water is entering a hollow chamber ( matrix box) I don't see how the distribution pipe will affect the water flow upwards through the bog. New water entering will fill the void from water exiting the bog to a steam or the pond.
I would still incorporate a stack to lower a pump into the bog to back flush .

 

[Meyer Jordan]

Is it necessary to have a diffuser pipe to distribute the water across the bog? If the water is entering a hollow chamber ( matrix box) I don't see how the distribution pipe will affect the water flow upwards through the bog. New water entering will fill the void from water exiting the bog to a steam or the pond
I would still incorporate a stack to lower a pump into the bog to back flush .

The diffuser pipe or centipede Is purposed to reduce water turbulence thereby allowing any TSS remaining in the water a chance to settle out.

 

[Gordo33]

The water entering the 'bog' should be pre-filtered in some manner in order to keep the TSS to the lowest possible level

s one reason that I prefer the use of the matrix cubes. Coupled with a reduced flow rate any TSS that is not captured by the pre-filter is allowed to settle out before it reaches the gravel layer.

I agree totally and presented this to @brokensword earlier in this thread. I would appreciate your feed back on this design . Access to the Matala pads for removal to clean periodically could be achieved with a vertical box .

I would think the same way a chamber can be created under the gravel with the matrix blocks a vertical chamber can be created to house Matala pads. Let the water flow through this first and then into the hollow chamber beforing the water travels up through the gravel. It may also allow debris to settle out if the flow slows enough.

 

[Lisak1]

I missed this whole discussion somehow! Let me just say - I approve of this thread. haha!

Also - @Meyer Jordan I so wish I had gotten that advice to never use landscape fabric in a bog BEFORE our build. We didn't put it in our upflow bog, but we did put it in our downflow to prevent the gravel from falling into the Aquablox. BIG MISTAKE. That stuff clogs so fast it's not even funny. And we didn't stop at one layer... oh, no. If one layer is good... well, you can imagine. I spent two summers pulling, digging, and cutting that stuff (substitute another S word here if you're the cursing type, as I am in real life) out. Finally had my boys help me dig out all the gravel and put in geo-grid in it's place. SOOOOO much better.

I honestly have never seen landscape fabric used in a way that WAS helpful - we lost an entire hedge because the previous owner had landscape fabric under the mulch to prevent weeds. Well, eventually it prevented the water from getting through AT ALL. The bushes all died from lack of water - just dumb. When we finally figured it out and dug it up, it was 100% clogged. You couldn't have designed a better water barrier if you tried! Oh, and we still got weeds in the hedge - they were growing in the layer of silt that the "weed barrier" had trapped! JUST USE MULCH PEOPLE!

 

[Gordo33]

@Meyer Jordan I have a question about the clean out pipe with a matrix box set up. Will a pipe large enough to hold a garden hose that would attach to the intake side of a water transfer pump work for back flushing the phyto filter? I constructed a small bog 5x2x1.5 ft using 2 matrix boxes. A cleanout pipe large enough to lower a pump into would significantly reduce the size of the phyto filter.

 

[Meyer Jordan]

@Meyer Jordan I have a question about the clean out pipe with a matrix box set up. Will a pipe large enough to hold a garden hose that would attach to the intake side of a water transfer pump work for back flushing the phyto filter? I constructed a small bog 5x2x1.5 ft using 2 matrix boxes. A cleanout pipe large enough to lower a pump into would significantly reduce the size of the phyto filter.

Never tried what you have suggested but it should work 'in theory' if located at the deepest point of the 'bog'. Did you slope the bottom (floor) of the 'bog'?

 

[Gordo33]

Never tried what you have suggested but it should work 'in theory' if located at the deepest point of the 'bog'. Did you slope the bottom (floor) of the 'bog'?

I made a slight slope towards the center. To facilitate pulling water through the distribution pipe for back flushing what would be the best location for the slits? My thoughts are along the sides since the pipe is located in the middle of the bog.

 

[Meyer Jordan]

I made a slight slope towards the center. To facilitate pulling water through the distribution pipe for back flushing what would be the best location for the slits? My thoughts are along the sides since the pipe is located in the middle of the bog.

If this will only be used for backflushing, I would limit the slits to the bottom 4" of the stand pipe. Make sure that the bottom of this stand pipe is capped

 

[Gordo33]

If this will only be used for backflushing, I would limit the slits to the bottom 4" of the stand pipe. Make sure that the bottom of this stand pipe is capped

To clarify:
In post #39 I was referring to slits in the horizontal distribution pipe. My plan is for the vertical stand pipe to be attached to the horizontal distribution pipe via a 90 degree elbow. So I would drop the hose in the vertical stand pipe and the water would be drawn through the horizontal distribution pipe. With this set up do you still recommend slits in the stand pipe?

 

[Meyer Jordan]

To clarify:
In post #39 I was referring to slits in the horizontal distribution pipe. My plan is for the vertical stand pipe to be attached to the horizontal distribution pipe via a 90 degree elbow. So I would drop the hose in the vertical stand pipe and the water would be drawn through the horizontal distribution pipe. With this set up do you still recommend slits in the stand pipe?

No. You want 100% of the water flow to be going through the slits in the distribution pipe.

 

[sondra256]

Do you use a "regular submersible sump pump" to lower down the centipede stack to back flush? Will it pump out all the sludge or do I need a different or more powerful kind of pump? Thanks for any help!

 

[GBBUDD]

Do you use a "regular submersible sump pump" to lower down the centipede stack to back flush? Will it pump out all the sludge or do I need a different or more powerful kind of pump? Thanks for any help!

This post is three years old . But to answer your question . I HAVE NOT SEEN ANYONE SAY THAT THEY HAD ANY HUGE AMOUNTS OF sediment in the snorkel clean out at most they will have a little dirty water for a few seconds when they drop a submersible pump down the snorkel. If you end up being the we exception and not the no r m th we y have what are called trash pumps these can suck up to 3/8 " sized waste and push it through the pump. I have gone as far as to take a garden hose and slide it down the snorkel into the cetipede where i let the hose dance in the water thus stirring up any debris then turn the discharge pump on for a good cleaning and i have still had next to nothing 3 years latter .

 

[Lisak1]

I loved re-reading this thread and seeing Meyer chime in - he's missed here.

I've dropped a portable little sump pump down my vault on a few occasions. A second or two of silty water and then nothing but clear, clean, sparkling pond water.